Sumco : Announcement Regarding Issuance of New Shares

[Translation]

September 30, 2021

To whom it may concern,

Company name: SUMCO Corporation

Representative: Mayuki Hashimoto, Representative Director CEO & Chairman of the Board (Code: 3436, TSE First Section)

Contact: Hiroshi Shibuya, Executive Officer General Manager of Public Relations & IR Department (Tel: [phone])

Announcement Regarding Issuance of New Shares

SUMCO Corporation (the "Company") hereby announces that it has resolved, at the meeting of the board of directors held on September 30, 2021, to issue new shares of the Company through a public offering.

Purpose of the Funding

The Company and its group companies (the "Company Group") produces high quality silicon wafers used in semiconductor devices, and has a wide range of product development capabilities and technological capabilities, covering large to small diameter silicon wafers, and by establishing a stable supply system through making the best use of such capabilities, the Company Group contributes to the development of society.

In particular, the Company is concentrating on the enhancement and improvement of its technological capabilities to meet the extremely strict quality and cost demands of customers, and is striving to raise the Company's standing in the semiconductor silicon wafer industry.

Against the backdrop of continued strong demand for semiconductors used for 5G, smartphones, data centers, automobiles and so on, demand for 300 mm silicon wafers is expected to continue to grow steadily. The supply that the Company can provide with the Company Group's current manufacturing facilities is not able to keep up with demand, and the market for 300 mm leading-edge silicon wafers, which are compatible with the most advanced technologies that are the driving force for improving the performance of semiconductors, is especially expected to achieve higher levels of growth.

Based on these circumstances, the Company will continue to appropriately implement its policy of raising the production capacity gradually (the "Successive Capacity Expansions") in response to customer demand to fulfill our supply responsibilities to them, while taking into consideration forecasts for supply and demand for the 300 mm leading-edge silicon wafer market from time to time and the length of time, etc. required for the construction and expansion of manufacturing facilities. Also, when conducting the Successive Capacity Expansions in the future, the Company intends to

Note: This press release has been prepared for the purpose of publicly announcing the Company's issuance of new shares, and not for the purpose of soliciting investment within or outside Japan. Please be sure to review the Japanese language prospectus and amendments thereto (if any) prepared by the Company prior to investing, and make any investment at your own responsibility and discretion.

This press release does not constitute an offer or sale of securities in the United States. The shares of common stock of the Company (the "securities") have not been and will not be registered under the U.S. Securities Act of 1933 (the "Securities Act"). The securities may not be offered or sold in the United States absent registration or an exemption from registration under the Securities Act. With respect to the issuance of new shares, the securities will not be registered in the United States.

prioritize supply to customers who have committed to long-term agreements with economically reasonable selling prices and durations of greater than our historically typical two to three years.

The miniaturization technology for the leading-edge semiconductors is constantly evolving, and customers are increasingly demanding the technology and quality required for 300 mm leading-edge silicon wafers that are compatible with new technologies. To establish production lines that meet such level of demand, it is necessary to introduce the production related facilities such as manufacturing and processing equipment and inspection equipment which have higher precision and performance and which are more expensive than the existing equipment.

Since the Company Group's existing plants in Japan are running out of the space for capacity expansions, the purpose of this funding is to introduce manufacturing equipment to cope with the Successive Capacity Expansions after constructing a new plant building and utility equipment and to establish a system which allows production to begin in stages.

The Company has endeavored to improve its financial strength in order to establish a strong financial base, which is essential for a sustainable increase in corporate value. Raising part of the funds for capital investment through a public offering will enable the Company to conduct the continuous Successive Capacity Expansions without impairing its financial flexibility and agility necessary for business operations, and therefore the Company believes it will contribute to the medium- to long-term improvement of corporate value.

Please see the "Announcement Regarding Capital Investment (Acquisition of Fixed Assets)" published on September 30, 2021 for details of the capital investment.

Issuance of new shares through public offering

(1)	Class and number of	60,000,000 shares of common stock of the Company,
	shares to be offered	being the aggregate of (i) through (iii) described below:
		(i)	15,000,000 shares of common stock of the
		Company, issued for purchase and underwriting by the
		Japanese Underwriters in the Japanese Offering,
		described in (4)(i) below;
		(ii)	37,174,000 shares of common stock of the
		Company, issued for purchase and underwriting by the
		International Underwriters in the International Offering,
		described in (4)(ii) below; and
		(iii)	A maximum of 7,826,000 shares of common
		stock of the Company, additionally issued for
		acquisition by the International Underwriters in the
		International Offering upon exercise of the option,
		described in (4)(ii) below.
(2)	Method of determination	The amount to be paid in will be determined on a day in
	of amount to be paid in	the period between October 12, 2021 (Tue) and October
		15, 2021 (Fri) (such date, the "Pricing Date") in
		accordance with the method set forth in Article 25 of the
		Regulations Concerning Underwriting of Securities, etc.
		promulgated by the Japan Securities Dealers
		Association (the "JSDA").

Note: This press release has been prepared for the purpose of publicly announcing the Company's issuance of new shares, and not for the purpose of soliciting investment within or outside Japan. Please be sure to review the Japanese language prospectus and amendments thereto (if any) prepared by the Company prior to investing, and make any investment at your own responsibility and discretion.

This press release does not constitute an offer or sale of securities in the United States. The shares of common stock of the Company (the "securities") have not been and will not be registered under the U.S. Securities Act of 1933 (the "Securities Act"). The securities may not be offered or sold in the United States absent registration or an exemption from registration under the Securities Act. With respect to the issuance of new shares, the securities will not be registered in the United States.

1. Amount of stated capital and additional capital reserves to be increased
2. Method of offering

The amount of stated capital to be increased is half of the maximum increase amount of stated capital, as calculated in accordance with the provisions of Article 14, Paragraph 1 of the Rules of Account Settlement of Corporations, with any fraction less than one yen resulting from the calculation being rounded up to the nearest one yen. The amount of capital reserves to be increased is the amount obtained by subtracting the said amount of stated capital to be increased from the maximum amount of increase of stated capital.

The Japanese offering and the international offering will be made simultaneously.

1. Japanese Offering:
   The offering to be made in Japan (the

"Japanese Offering") will be a public offering, and Japanese underwriters (the "Japanese Underwriters") shall purchase and underwrite all of the shares through public offering in Japan.

1. International Offering:
   In the offering to be made outside Japan (with

the offering in the United States restricted to sales to qualified institutional buyers under Rule 144A of the U.S. Securities Act of 1933) (the "International Offering") the aggregate number of shares will be severally purchased and underwritten by international underwriters (the "International Underwriters", and collectively with the Japanese Underwriters, the "Underwriters"). The Company shall also grant the International Underwriters the option to acquire additional newly issued shares of common stock of the Company, as described in (1)(iii) above.

With regard to the number of shares to be offered described in (i) and (ii) above, the number of shares to be offered is planned to be 15,000,000 shares in the Japanese Offering and 45,000,000 shares in the International Offering (37,174,000 shares described in (1)(ii) above and 7,826,000 additional shares upon exercise of the option in (1)(iii) above). However, the final breakdown will be determined on the Pricing Date by taking into account market demand and other conditions.

The issue price (offer price) with regard to each of (i) and (ii) shall be determined on the Pricing Date in accordance with the method stated in Article 25 of the Regulations Concerning Underwriting of Securities, etc., of the JSDA, based on the preliminary pricing

Note: This press release has been prepared for the purpose of publicly announcing the Company's issuance of new shares, and not for the purpose of soliciting investment within or outside Japan. Please be sure to review the Japanese language prospectus and amendments thereto (if any) prepared by the Company prior to investing, and make any investment at your own responsibility and discretion.

This press release does not constitute an offer or sale of securities in the United States. The shares of common stock of the Company (the "securities") have not been and will not be registered under the U.S. Securities Act of 1933 (the "Securities Act"). The securities may not be offered or sold in the United States absent registration or an exemption from registration under the Securities Act. With respect to the issuance of new shares, the securities will not be registered in the United States.

		terms calculated by multiplying the closing price in
		regular trading of the shares of common stock of the
		Company on the Tokyo Stock Exchange, Inc. on the
		Pricing Date (or, if no closing price is quoted, the
		closing price of the immediately preceding date) by a
		number between 0.90 and 1.00 (with any fraction less
		than one yen being rounded down), taking into account
		market demand and other conditions.
(5)	Consideration for the	The Company shall not pay any underwriting
	Underwriters	commissions to the Underwriters, although the
		aggregate amount of the difference between (a) the issue
		price (offer price) in the issuance of new shares through
		the Japanese Offering and the International Offering,
		and (b) the amount to be paid in to the Company by the
		Underwriters shall constitute proceeds to the
		Underwriters.
(6)	Subscription period (for	The subscription period is from the business day
	the Japanese Offering)	immediately following the Pricing Date to the second
		business day following the Pricing Date.
(7)	Payment date	The payment date is a day in the period from October
		18, 2021 (Mon) to October 21, 2021 (Thu); provided,
		however, that such day is the fourth business day
		following the Pricing Date.
(8)	Deposit for Subscription	Same as the issue price (offer price) per share.
(9)	Subscription unit	100 shares

1. The amount to be paid in, the amount of stated capital and capital reserves to be increased, the issue price (offer price), and any other matters necessary for this issuance of new shares through public offering will be determined at the discretion of Mr. Mayuki Hashimoto, Representative Director, Chairman and CEO of the Company or person delegated by him.
2. The Japanese Offering shall be subject to the registration taking effect under the Financial Instruments and Exchange Act of Japan.

1. Change in the total number of issued shares as a result of the issuance of new shares

through public offering this time
Total number of issued shares at present (as at	290,175,139 shares
September 30, 2021):
Increased number of shares as a result of the	60,000,000 shares	(Note)
issuance of new shares through public
offering:
Total number of issued shares after the	350,175,139 shares	(Note)
issuance of new shares through public
offering:

(Note) These figures are based on the assumption that the International Underwriters exercise all of the options set forth in (1)(iii) of "Issuance of new shares through public offering" above.

Note: This press release has been prepared for the purpose of publicly announcing the Company's issuance of new shares, and not for the purpose of soliciting investment within or outside Japan. Please be sure to review the Japanese language prospectus and amendments thereto (if any) prepared by the Company prior to investing, and make any investment at your own responsibility and discretion.

This press release does not constitute an offer or sale of securities in the United States. The shares of common stock of the Company (the "securities") have not been and will not be registered under the U.S. Securities Act of 1933 (the "Securities Act"). The securities may not be offered or sold in the United States absent registration or an exemption from registration under the Securities Act. With respect to the issuance of new shares, the securities will not be registered in the United States.

2. Use of proceeds

1. Use of proceeds procured

Of the maximum estimated amount of total proceeds of 127,969,000,000 yen from the Japanese Offering and the International Offering, (i) 78.6 billion yen will be applied to the capital investment related to a new plant building and utility equipment at our main manufacturing site in Japan (Imari, Saga Prefecture) by the end of December 2023 and (ii) the remainder will be applied to the capital investment for manufacturing equipment for 300 mm leading-edge silicon wafers at such plant by the end of December 2024.

The proceeds mentioned above are planned to be invested in highly safe financial instruments, etc. until they are actually applied to the capital investment.

The Company Group's policy of investment to reinforce 300 mm leading-edge silicon wafer production capacity.

The Company Group produces high quality silicon wafers used in semiconductor devices, and has a wide range of product development capabilities and technological capabilities, covering large to small diameter silicon wafers, and by establishing a stable supply system through making the best use of such capabilities, the Company Group contributes to the development of society.

In particular, the Company is concentrating on the enhancement and improvement of its technological capabilities to meet the extremely strict quality and cost demands of customers, and is striving to raise the Company's standing in the semiconductor silicon wafer industry.

Against the backdrop of continued strong demand for semiconductors used for 5G, smartphones, data centers, automobiles and so on, demand for 300 mm silicon wafers is expected to continue to grow steadily. The supply that the Company can provide with the Company Group's current manufacturing facilities is not able to keep up with demand, and the market for 300 mm leading-edge silicon wafers, which are compatible with the most advanced technologies that are the driving force for improving the performance of semiconductors, is especially expected to achieve higher levels of growth.

Based on these circumstances, the Company will continue to appropriately implement its policy of the Successive Capacity Expansions in response to customer demand to fulfill our supply responsibilities to them, while taking into consideration forecasts for supply and demand for the 300 mm leading-edge silicon wafer market from time to time and the length of time, etc. required for the construction and expansion of manufacturing facilities. Also, when conducting the Successive Capacity Expansions in the future, the Company intends to prioritize supply to customers who have committed to long-term agreements with economically reasonable selling prices and durations of greater than our historically typical two to three years.

The miniaturization technology for the leading-edge semiconductors is constantly evolving, and customers are increasingly demanding the technology and quality required for 300 mm leading-edge silicon wafers that are compatible with new technologies. To establish production lines that meet such level of demand, it is necessary to introduce the production related facilities such as manufacturing and processing equipment and inspection equipment which have higher precision and performance and which are more expensive than the existing equipment.

Note: This press release has been prepared for the purpose of publicly announcing the Company's issuance of new shares, and not for the purpose of soliciting investment within or outside Japan. Please be sure to review the Japanese language prospectus and amendments thereto (if any) prepared by the Company prior to investing, and make any investment at your own responsibility and discretion.

This press release does not constitute an offer or sale of securities in the United States. The shares of common stock of the Company (the "securities") have not been and will not be registered under the U.S. Securities Act of 1933 (the "Securities Act"). The securities may not be offered or sold in the United States absent registration or an exemption from registration under the Securities Act. With respect to the issuance of new shares, the securities will not be registered in the United States.