To provide a worm wheel ensuring a clearance between itself and an adjacent member and to manufacture the worm wheel at a high efficiency and low cost.

A worm wheel 31 is formed by making a gearing 62 made of a synthetic resin adhere to the outer periphery of a metal wheel 61. The wheel 61 comprises a hub section 63 fitting to a sensor output shaft 7 from the outside, a rim section 65, to the outer peripheral face with the gearing 62 made to adhere, and a disk section 66 connecting the hub section 63 and a rim section. The wheel 61 is formed with a shaft hole 67 fitted with the sensor output shaft 7 from the inside, and the hub section 63 offsets specified quantity L in the axial direction (the left direction in the drawing) to the rim section 65, as a result, a recessed section 68 is formed at the center of the rear face of the wheel 61.