Provided is a worm wheel that allows the residual stress in the plastic gear forming member thereof to be reduced, and suited for compact design. The worm wheel comprises a metallic core member (30) and a plastic gear forming member (20) formed on an outer periphery of the core member. In particular, the core member includes a boss portion (31) defining a pivot portion, an intermediate portion (32) extending radially from the outer periphery of the boss portion, and a cylindrical portion (33) connected to a radially outer end of the intermediate portion and having the gear forming member molded thereon coaxially with the boss, the cylindrical portion being formed with through holes (34) or cutouts (36) passed radially therethrough.