To reduce a load on an electric motor for a power assisted motor-driven power steering apparatus. The present invention includes side projecting portions secured to an input shaft with an upwardly projecting tab as a first stopper secured to a vehicle body at a position corresponding to the side projecting portions. The upwardly projecting tab being provided for restricting a swing range of the side projecting portions. The side projecting portions are secured to an output shaft. A downwardly projecting portion is provided as a second stopper secured to the vehicle body at a position corresponding to the side projecting portions. The downwardly projecting portion being provided for restricting a swing range of the side projecting portions.