To more exactly learn the fully closed position of a throttle valve.

The fully closed position of a throttle valve 14 is learned before starting an engine. In controlling the throttle valve 14 after learning, when the throttle valve 14 is in a sate pushing a stopper, the state is detected based on an overcurrent carried to a motor 15. The learned fully closed position is corrected to the opening of the throttle valve detected by a throttle position sensor 13 to adjust the fully closed position. For every repeat of the pushing state by the throttle valve 14, a compensation degree Δ is added to the fully closed position to successively adjust the fully closed position.