A cancer vaccine that can be orally administered can be provided through the use of a transformed Bifidobacterium capable of expressing and displaying a WT1 protein. The WT1 protein expressed and displayed by the transformed Bifidobacterium is a protein covering most of a WT1 protein unlike a WT1 peptide vaccine restricted to a certain HLA. A cancer vaccine using the transformed Bifidobacterium as an active ingredient is applicable to patients of various HLA types.