PURPOSE: To provide a throttle opening position control device wherein idle control can be performed with no delay of starting action by a simple constitution.

CONSTITUTION: A throttle valve 2 energized to a valve closing side is provided in an intake passage 1 of an engine. A valve closing stopper position of the throttle valve 2 is determined by an idle actuator 4 formed of a DC motor. An ECU 13 controls a direction and time of driving the idle actuator 4 in order to provide a target engine speed or a target throttle opening at idle time. The ECU 13 gives a drive signal for a predetermined time T in a side of opening the throttle valve 2 to the idle actuator 4 in a non-idle condition, to transfer the valve closing stopper position to a valve opening side by a predetermined degree Δα relating to the valve closing stopper position in the idle condition just before generating the non-idle condition.