Provided are a forging method and a full-enclosed forging die which contribute to alleviation of an enclosing force applied to dies and in which a relatively small enclosing apparatus can be used even with respect to larger-sized products. Further, provided is a tripod type constant velocity universal joint using a tripod member molded with such a full-enclosed forging die. Using a full-enclosed forging die including openable/closable dies (11, 12) and punches (14, 15) for pressing a material between the dies (11, 12), a product (tripod member) (16) including a boss portion (18) and shaft portions (17) protruded radially from the boss portion (18) is molded. A projection area in a boss-portion axial direction toward a die (11, 12) side of the boss portion (18) is made to be smaller than another projection area in the boss-portion axial direction toward the die side, the another projection area being defined when a radially outer surface is formed as a single convex curved surface about a boss-portion axial center.