PROBLEM TO BE SOLVED: To provide an antibody that binds to PD-L1, an antigen-binding fragment thereof, and a method of use. A heavy chain CDR1 sequence that is an isolated antibody or fragment thereof that binds to PD-L1 and has at least 80% homology to an amino acid sequence selected from the group consisting of a particular sequence; a particular Heavy chain CDR2 sequence having at least 80% homology with the amino acid sequence selected from the group consisting of sequences; heavy chain CDR3 sequence having at least 80% homology with the amino acid sequence selected from the group consisting of specific sequences; Light chain CDR1 sequence having at least 80% homology with the amino acid sequence selected from the group consisting of a particular sequence; light chain CDR2 having at least 80% homology to the amino acid sequence selected from the group consisting of a particular sequence The isolated antibody or fragment thereof comprising a light chain CDR3 sequence having at least 80% homology to a sequence; and an amino acid sequence selected from the group consisting of a particular sequence. [Selection diagram] Fig. 1【課題】PD-L1に結合する抗体及びその抗原結合断片、並びに使用方法の提供。【解決手段】PD-L1に結合する単離された抗体またはその断片であって、特定の配列からなる群から選択されるアミノ酸配列と少なくとも80%の相同性を有する重鎖CDR1配列;特定の配列からなる群から選択されるアミノ酸配列と少なくとも80%の相同性を有する重鎖CDR2配列;特定の配列からなる群から選択されるアミノ酸配列と少なくとも80%の相同性を有する重鎖CDR3配列;特定の配列からなる群から選択されるアミノ酸配列と少なくとも80%の相同性を有する軽鎖CDR1配列;特定の配列からなる群から選択されるアミノ酸配列と少なくとも80%の相同性を有する軽鎖CDR2配列;及び特定の配列からなる群から選択されるアミノ酸配列と少なくとも80%の相同性を有する軽鎖CDR3配列を含む、前記単離された抗体またはその断片。【選択図】図1