Sumitomo Metal Mining : (Revision) Partial Revision to the Business Report, Consolidated Financial Statements and Non-consolidated Financial Statements for the 97th Ordinary General Meeting of Shareholders

June 20, 2022

To our shareholders

Company name: Sumitomo Metal Mining Co., Ltd.

Representative: Akira Nozaki, President & Representative Director

(Code number: 5713, PRIME, Tokyo Stock Exchange)

Contact: Daiji Toyama, PR & IR Department

(TEL: +81-3−3436−7705)

(Revision) Partial Revision to the Business Report, Consolidated Financial Statements

and Non-consolidated Financial Statements for the 97th Ordinary General

Meeting of Shareholders

Sumitomo Metal Mining Co., Ltd. (the "Company") hereby announces that there was misstatement in the Consolidated Financial Statements & Non-consolidated Financial Statements for the 97th Ordinary General Meeting of Shareholders and revisions are made as outlined below.

The revised parts are underlined.

Revised point

2. Convocation Notice of the 97th Ordinary General Meeting of Shareholders Business Report for Shareholders Meeting, Page 54

5.(4) 2) b. Method of calculating the amount reflecting individual performance

(Before Revision)

b. Method of calculating the amount reflecting individual performance

With respect to the amount reflecting individual performance related to the basic remunerations for the President and Director, the total score shall be calculated based on a 4:1 ratio of "achievement level of the published forecast of company wide performance" and "achievement level of safety record" for the previous fiscal year. The individual performance evaluation coefficient is determined, in the range of 90% to 160%, based on the predetermined coefficient table according to the total score (in this table, profit before tax is taken into account), and the amount reflecting individual performance is calculated.

With respect to the amount reflecting individual performance related to the basic remunerations for Directors who concurrently serve as executive officers with special titles (Executive Vice President, Senior Managing Executive Officers, Managing Executive Officers), the total score shall be calculated by scoring the "comparison of division results with the previous fiscal year," "achievement level of the published forecast of division results," "the degree of attainment of personal targets under medium-to long-term

management strategies," and "achievement level of safety record" for the previous fiscal year, respectively, and then weighing them based on the following ratio: "comparison of division results with the previous fiscal year: achievement level of the published forecast of division results: the degree of attainment of personal targets: achievement level of safety record=3:3:4:1" and the amount reflecting individual performance is calculated in the same manner as above.

With respect to the amount reflecting individual performance related to the bonus for the President and Director, the total score shall be calculated based on a 4:1 ratio of "achievement level of the published forecast of company-wide performance" and "achievement level of safety record" for the current fiscal year. With respect to the amount reflecting individual performance related to the bonus for Directors who concurrently serve as executive officers, in view of the COVID19 pandemic, only the achievement of the published forecast shall be considered for the current fiscal year concerning the division results, and the total score shall be calculated as follows: "achievement level of the published forecast of division results: the degree of attainment of personal targets: achievement level of safety record = 6:4:1" for the current fiscal year, respectively, and the amount reflecting individual performance is calculated in the same manner as above.

Amount reflecting individual performance related to the basic remunerations = Amount of basic remunerations for each position x Certain coefficients not based on performance x Individual performance evaluation coefficient

Amount reflecting individual performance related to the bonus = Amount of bonus for each position x Certain coefficients not based on performance x Individual performance evaluation coefficient

(After Revision)

b. Method of calculating the amount reflecting individual performance

With respect to the amount reflecting individual performance related to the basic remunerations for the President and Director, the total score shall be calculated based on a 4:1 ratio of "achievement level of the published forecast of company wide performance" and "achievement level of safety record" for the previous fiscal year. The individual performance evaluation coefficient is determined, in the range of 90% to 160%, based on the predetermined coefficient table according to the total score (in this table, profit before tax is taken into account), and the amount reflecting individual performance is calculated.

With respect to the amount reflecting individual performance related to the basic remunerations for Directors who concurrently serve as executive officers with special titles (Executive Vice President, Senior Managing Executive Officers, Managing Executive Officers), the total score shall, in principle, be calculated by scoring the "comparison of division results with the previous fiscal year," "achievement level of the published forecast of division results," "the degree of attainment of personal targets under medium-to long-termmanagement strategies," and "achievement level of safety record" each for the previous fiscal year, weighing them, and calculating in the same manner as above. However, in light

of the severity of the impact of the COVID-19 pandemic in the previous fiscal year, in the current fiscal year, evaluations of division results only take into consideration "achievement level of the published forecast of division results," which does not include "comparison of division results with the previous fiscal year," and weighs each of them for the previous fiscal year based on the following ratio: "achievement level of the published forecast of division results: the degree of attainment of personal targets: achievement level of safety record = 6:4:1."

With respect to the amount reflecting individual performance related to the bonus for the President and Director, the total score shall be calculated based on a 4:1 ratio of "achievement level of the published forecast of company-wide performance" and "achievement level of safety record" for the current fiscal year. With respect to the amount reflecting individual performance related to the bonus for Directors who concurrently serve as executive officers, the total score shall be calculated as follows: "comparison of division results with the previous fiscal year," "achievement level of the published forecast of division results," "the degree of attainment of personal targets" and "achievement level of safety record" each for the current fiscal year at a ratio of 2:4:4:1, and the amount reflecting individual performance is calculated in the same manner as above.

Amount reflecting individual performance related to the basic remunerations = Amount of basic remunerations for each position x Certain coefficients not based on performance x Individual performance evaluation coefficient

Amount reflecting individual performance related to the bonus = Amount of bonus for each position x Certain coefficients not based on performance x Individual performance evaluation coefficient

2. Convocation Notice of the 97th Ordinary General Meeting of Shareholders Consolidated Financial Statements for Shareholders Meeting, Page 57

Consolidated Statement of Financial Position

(Before Revision)

Consolidated Statement of Financial Position

(as of March 31, 2022)

(Millions of yen)

Items	Amount	Items	Amount
Assets		Liabilities
Current assets		Current liabilities
Cash and cash equivalents	213,977	Trade and other payables	206,013
Trade and other receivables	187,310	Bonds and borrowings	91,106
Other financial assets	49,342	Other financial liabilities	7,027
Inventories	420,136	Income taxes payable	24,940
Other current assets	44,354	Provisions	6,101
Total current assets	915,119	Other current liabilities	19,727
Non-current assets		Total current liabilities	354,914
Property, plant and equipment	507,822	Non-current liabilities
Intangible assets and goodwill	56,586	Bonds and borrowings	240,126
Investment property	3,477	Other financial liabilities	9,579
Investments accounted for using	368,751	Provisions	25,107
equity method
Other financial assets	387,507	Retirement benefit liability	5,310
Deferred tax assets	1,645	Deferred tax liabilities	75,631
Other non-current assets	27,849	Other non-current liabilities	671
Total non-current assets	1,353,637	Total non-current liabilities	356,424
		Total liabilities	711,338
		Equity
		Share capital	93,242
		Capital surplus	90,213
		Treasury shares	(38,056)
		Other components of equity	124,304
		Retained earnings	1,175,626
		Total equity attributable to	1,445,329
		owners of parent
		Non-controlling interests	112,089
		Total equity	1,557,418
Total assets	2,268,756	Total liabilities and equity	2,268,756

(After Revision)

Consolidated Statement of Financial Position

(as of March 31, 2022)

(Millions of yen)

Items	Amount	Items	Amount
Assets		Liabilities
Current assets		Current liabilities
Cash and cash equivalents	213,977	Trade and other payables	206,013
Trade and other receivables	187,310	Bonds and borrowings	120,983
Other financial assets	49,342	Other financial liabilities	7,027
Inventories	420,136	Income taxes payable	24,940
Other current assets	44,354	Provisions	6,101
Total current assets	915,119	Other current liabilities	19,727
Non-current assets		Total current liabilities	384,791
Property, plant and equipment	507,822	Non-current liabilities
Intangible assets and goodwill	56,586	Bonds and borrowings	210,249
Investment property	3,477	Other financial liabilities	9,579
Investments accounted for using	368,751	Provisions	25,107
equity method
Other financial assets	387,507	Retirement benefit liability	5,310
Deferred tax assets	1,645	Deferred tax liabilities	75,631
Other non-current assets	27,849	Other non-current liabilities	671
Total non-current assets	1,353,637	Total non-current liabilities	326,547
		Total liabilities	711,338
		Equity
		Share capital	93,242
		Capital surplus	90,213
		Treasury shares	(38,056)
		Other components of equity	124,304
		Retained earnings	1,175,626
		Total equity attributable to	1,445,329
		owners of parent
		Non-controlling interests	112,089
		Total equity	1,557,418
Total assets	2,268,756	Total liabilities and equity	2,268,756