An antibody that binds to Mucin17 (Muc17) is disclosed. The antibody of the present invention preferably binds to the peptide of SEQ ID NO:3 and does not bind to the peptide of SEQ ID NO:4 or the peptide of SEQ ID NO:5. Also disclosed are an anti-cancer agent, preferably an anti-cancer agent for pancreatic cancer, which comprises the antibody of the present invention, as well as a method of diagnosing cancer using the antibody of the present invention, preferably the antibody of the present invention that does not bind to the secreted-form of Muc17.
