The object aims to provide: a novel tumor antigen； a novel therapeutic agent useful in a method for treating a malignant neoplasm by utilizing the tumor antigen； and a tumor antigen which can be used as the therapeutic agent. Thus, disclosed are: a novel tumor antigen which has an epitope capable of inducing a Th1 cell which is a CD4-positive T cell specific to Survivin； and use of the tumor antigen. Specifically disclosed is a polypeptide which comprises an amino acid sequence depicted in SEQ ID NO:17 or the like and has an activity to cause the production of a cytokine by a Th cell that is a cell specific to Survivin. The peptide can induce a Th cell that is specific to Survivin and can cause the production of a cytokine by the Sur/Th cell when the peptide is incubated together with an antigen-presenting cell and a CD4-positive T cell.
