To provide antibody combined with polypeptide (preferably monoclonal antibody), a kit for diagnosis containing such an antibody, and a method using such an antibody in order to inhibit development of prostate cancer.

This is the method for detecting prostate cancer in a patient, which comprises a process (a) for bringing a biological sample obtained from the patient into contact with a bonding factor combinable with polypeptide, where polypeptide contains immunogenic part of prostate protein or its engineered body, while protein contains nucleotide sequence shown in sequencing numbers 2-3, 5-107, 109-111, 115-171, 173-175, 177 and 179-224, complementary body of the nucleotide sequence, and amino acid sequence coded by DNA molecule provided with sequencing selected from sequencing groups which consist of the engineered body on nucleotide sequence; and a process (b) for detecting protein or polypeptide combined with bonding factor from the sample to detect prostate cancer in the patient.