BISPECIFIC ANTIBODY

Provided are a novel antibody usable as an antitumor agent and an antitumor agent that comprises a molecule containing the antibody, etc. as an active ingredient. An antibody that contains heavy chain CDRH1 comprising the amino acid sequence represented by SEQ ID NO: 54, heavy chain CDRH2 comprising the amino acid sequence represented by SEQ ID NO: 55, heavy chain CDRH3 comprising the amino acid sequence represented by SEQ ID NO: 56, light chain CDRL1 comprising the amino acid sequence represented by SEQ ID NO: 57 or light chain CDRL1 comprising an amino acid sequence that is identical with the amino acid sequence represented by SEQ ID NO: 57 except that the seventh amino acid is W and/or the eighth amino acid is K, light chain CDRL2 comprising the amino acid sequence represented by SEQ ID NO: 58, and light chain CDRL3 comprising the amino acid sequence represented by SEQ ID NO: 59 or light chain CDRL3 comprising an amino acid sequence that is identical with the amino acid sequence represented by SEQ ID NO: 57 except that the second amino acid is A or S; or a binding fragment of the antibody.