An electric power steering apparatus having a displacing mechanism in which a fitting hole potion is provided to a gear housing for fitting with and holding a bearing to which a worm shaft for transmitting rotating force of a steering assisting motor to a steering shaft provided with a worm wheel is fitted, the portion being formed of a pair of split members formed by splitting the portion into two, one split member being movable toward the other split member to adjust a distance between a shaft center of the worm shaft and a rotation center of the worm wheel.