The object aims to provide: a novel tumor antigen； a noveltherapeutic agent useful in a method for treating a malignantneoplasm by utilizing the tumor antigen； and a tumor antigenwhich can be used as the therapeutic agent. Thus, disclosed are:a novel tumor antigen which has an epitope capable of inducing aTh1 cell which is a CD4-positive T cell specific to Survivin； anduse of the tumor antigen. Specifically disclosed is a polypeptidewhich comprises an amino acid sequence depicted in SEQ ID NO:17or the like and has an activity to cause the production of acytokine by a Th cell that is a cell specific to Survivin. Thepeptide can induce a Th cell that is specific to Survivin and cancause the production of a cytokine by the Sur/Th cell when thepeptide is incubated together with an antigen-presenting cell anda CD4-positive T cell.
