To provide a cancer specific antigen peptide which specifically expresses against to cancer such as an inoperable advanced/relapsed lung cancer, etc., and to provide a vaccine therapy using the same.

The cancer specific antigen peptide is encoded by a gene sequence of the cancer specific antigen gene having a specific base sequence and has a specific amino acid sequence originated from a cancer specific antigen protein having a specific amino acid sequence. The peptide induces a tumor-specific cytotoxic T cell in HLA-B15 restriction, and/or is recognized by the tumor-specific cytotoxic T cell and has an antitumor activity and expresses in cancer cell. The vaccine comprises the antigen peptide specific to the cancer.