PROBLEM TO BE SOLVED: To provide an antitumor drug which is excellent in terms of antitumor effect and safety.SOLUTION: There is provided an antibody-drug conjugate in which an antitumor compound represented by the following formula is conjugated to an antibody via a linker having a structure represented by the following formula: -L-L-L-NH-(CH)n-L-L-L-, wherein the antibody is connected at the terminal of L, and the antitumor compound is connected at the terminal of Lwith a nitrogen atom of an amino group at position 1 as a connecting position.SELECTED DRAWING: None【課題】抗腫瘍効果と安全性面に優れる抗腫瘍薬の提供。【解決手段】下記式で示される抗腫瘍性化合物と抗体とを、次式：-L１-L２-LＰ-NH-(CH2)n１-Lａ-Lｂ-Lｃ-で示される構造のリンカーを介して結合させたことを特徴とする抗体－薬物コンジュゲート（抗体はL１の末端において結合し、抗腫瘍性化合物は、１位のアミノ基の窒素原子を結合部位として、Lｃの末端において結合する）。【選択図】なし
