It is intended to provide an antitumor drug having an excellent therapeutic effect, which is excellent in terms of antitumor effect and safety. There is provided an antibody-drug conjugate in which an antitumor compound represented by the following formula is conjugated to an anti-TROP2 antibody via a linker having a structure represented by the following formula: -L1-L2-LP-NH-(CH2)n1-La-(CH2)n2-C(=O)- wherein the anti-TROP2 antibody is connected to the terminal of L1, and the antitumor compound is connected to the carbonyl group of the -(CH2)n2-C(=O)- moiety with the nitrogen atom of the amino group at position 1 as a connecting position.抗腫瘤效果及安全性面優異、具有優異治療效果的抗腫瘤藥之提供。提供一種抗體-藥物結合物(Antibody-Drug Conjugate),其特徵為將下式所示的抗腫瘤性化合物與抗TROP2抗體,介隔下式:-L1-L2-LP-NH-(CH2)n1-La-(CH2)n2-C(=O)-所示的結構之連接物而結合(抗TROP2抗體係於L1之末端結合,抗腫瘤性化合物係將第1位之胺基之氮原子作為結合部位,與-(CH2)n2-C(=O)-部分之羰基結合)。