PROBLEM TO BE SOLVED: To provide an antibody specific for FcRH5, a composition comprising the antibody useful for the treatment of a hematopoietic tumor in a mammal, and a method for using the composition for such a purpose.SOLUTION: According to the present invention, there are provided humanized anti-FcRH5 antibodies, which comprise specific sequences, and fragments thereof; antibody-drug conjugates bound to cytotoxic substances via antibodies and linkers; compositions comprising them; and methods for inhibiting cell proliferation of lymphoma, etc., using these compositions.SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT【課題】FcRH5に特異的な抗体、哺乳類における造血系腫瘍の治療に有用な前記抗体を含む組成物、ならびに前記目的のための前記組成物の使用方法の提供。【解決手段】特定の配列を含むヒト化抗ヒトFcRH5抗体、その断片、抗体とリンカーを介して細胞傷害性物質と結合した抗体-薬剤接合体、及びこれらを含む組成物、並びにこれら組成物を用いたリンパ腫等の細胞増殖の抑制方法の提供。【選択図】なし