Abstract: A shift range switching device of a vehicle includes a fixing member provided in a vicinity of an external-toothed gear, an electric motor, an eccentric shaft provided on an output shaft, the external-toothed gear rotatably supported by the eccentric shaft, and a ring-shaped double-toothed gear provided on an outer circumference of the external-toothed gear. The shift range switching device includes internal teeth defined on an inner circumference of the double-toothed gear and engaged with external teeth of the external-toothed gear and the external-toothed gear defined on an outer circumference of the double-toothed gear and engaged with an output gear. The shift range switching device includes a restriction portion provided on one of the external-toothed gear and the fixing member and a restricted portion provided on the other of the external-toothed gear and the fixing member and engaged with the restriction portion.