To improve follow-up property of engine speed to operating torque of a throttle regulating device during operation of an idling speed regulating device.

An idling speed regulating device is so constituted that a throttle lever 4 at the time of idling is rotated in a direction of opening a throttle valve 3 by a free lever 5 rotatably supported to a throttle shaft 2 of the throttle valve and rotated by an actuator 10. In this case, an impinging part 5b of an SAS 12 of the free lever 5 is provided with a V-shape recessed part, and the V-shape recessed part is brought into contact with the pointed tip of the SAS 12.