Sumitomo Metal Mining Co., Ltd., at its 90th ordinary general meeting of shareholders convened on June 29, 2015, increased its number of outside directors from one to two. In tandem with this move, at the board of directors meeting held after the general meeting of shareholders it was decided to add one new member to the independent committee established in line with the company's takeover defense measures. The company appointed Mr. Hitoshi Taimatsu as member of the independent committee.

At June 2015, he is professor, Graduate School of Engineering and Resource Science of Akita University and director, Sumitomo Metal Mining Co., Ltd.