A resin portion of an output shaft has a large diameter section, from which one end portion of a rod outwardly projects, and an intermediate diameter section, which extends from the large diameter section in an axial direction and is rotatably supported by a housing. A gear portion is formed in an outer peripheral surface of the large diameter section and is meshed with a final gear. A recess is recessed in the axial direction in the large diameter section and extends in the circumferential direction along an entire circumferential extent of the rod. The intermediate diameter section is continuously filled with resin in a region, which extends from an outer peripheral surface of the rod to an outer peripheral surface of the intermediate diameter section in the radial direction, along the entire circumferential extent of the rod.