PROBLEM TO BE SOLVED: To provide an antibody that specifically recognizes a WT1 peptide/HLA-A24 composite or an antigen-binding fragment thereof.SOLUTION: An anti-WT1 peptide/HLA-A24 composite antibody or an antigen-binding fragment thereof consists of: a heavy chain including VH-CDR1 made up of an amino acid sequence shown in sequence number 8 of a sequence table, VH-CDR2 made up of an amino acid sequence shown in sequence number 9 of the table, and VH-CDR3 made up of an amino acid sequence shown in sequence number 10 of the table; and a light chain including VL-CDR1 made up of an amino acid sequence shown in sequence number 11 of the sequence table, VL-CDR2 made up of an amino acid sequence shown in sequence number 12 of the table, and VL-CDR3 made up of an amino acid sequence shown in sequence number 13 of the table.SELECTED DRAWING: Figure 1【課題】WT1ペプチド/HLA-A24複合体を特異的に認識する抗体又はその抗原結合性フラグメントを提供すること。【解決手段】配列表の配列番号8に示されるアミノ酸配列からなるVH-CDR1、配列番号9に示されるアミノ酸配列からなるVH-CDR2及び配列番号10に示されるアミノ酸配列からなるVH-CDR3を含む重鎖、並びに、配列表の配列番号11に示されるアミノ酸配列からなるVL-CDR1、配列番号12に示されるアミノ酸配列からなるVL-CDR2及び配列番号13に示されるアミノ酸配列からなるVL-CDR3を含む軽鎖からなる抗WT1ペプチド/HLA-A24複合体抗体又はその抗原結合性フラグメント。【選択図】図1