Provided is an anti-EphA4 antibody capable of binding to EphA4 and enhancing the cleavage of EphA4, and a pharmaceutical composition comprising the antibody as an active ingredient. The anti-EphA4 antibody comprises a heavy chain comprising a heavy chain CDR1 of SEQ ID NO: 30; a heavy chain CDR2 of SEQ ID NO: 31; and a heavy chain CDR3 of SEQ ID NO: 32; and a light chain comprising a light chain CDR1 of SEQ ID NO: 33; a light chain CDR2 of SEQ ID NO: 34; and a light chain CDR3 of SEQ ID NO: 35, or a heavy chain comprising a heavy chain CDR1 of SEQ ID NO: 42; a heavy chain CDR2 of SEQ ID NO: 31; and a heavy chain CDR3 of SEQ ID NO: 43; and a light chain comprising a light chain CDR1 of SEQ ID NO: 44; a light chain CDR2 of SEQ ID NO: 34; and a light chain CDR3 of SEQ ID NO: 35.