An electric variable valve timing apparatus includes a sprocket unit and an electric motor. The electric motor is fixed to a chain cover with bolts. The chain cover includes plural bosses each having an internal thread to which one of the bolts is threaded. The bosses extend from the chain cover toward the sprocket unit to positions at which the bosses face an outer periphery of the sprocket unit in a radial direction. The bosses are arranged such that, when the sprocket unit moves downward from an attaching position, at which the sprocket unit is attached to the camshaft, at least two bosses are engaged with the sprocket unit to restrict downward movement of the sprocket unit, and that the sprocket unit is allowed to move between a location outside of a space covered by the chain cover and the attaching position.