It is intended to provide an anti-human CD26 antibody which permits analysis, etc., of the expression of CD26 in cancer tissues, immune tissues, or the like, for example, in order to select a patient applicable to treatment or to monitor therapeutic effects, and can also be used in immunostaining. The present invention relates to an anti-human CD26 monoclonal antibody or an antigen-binding fragment thereof, binding to an epitope which is recognized by a monoclonal antibody produced by a hybridoma deposited under Accession No. NITE BP-01642, a hybridoma deposited under Accession No. NITE BP-01643, or a hybridoma deposited under Accession No. NITE BP-01644.
