PURPOSE: To provide an engine idling speed control device which can adjust the idling speed to the target value with high responsiveness and high accuracy despite varying rate-of-flow characteristics of a suction air amount adjusting means.

CONSTITUTION: An engine idling speed control device includes a suction air amount adjusting means 7 to adjust the suction air amount Qa supplied to an engine E, an ECU 15A to control the suction air amount adjusting means on the basis of various pieces of sensor information, and a rate-of-flow characteristic map 30 which indicates the relationship between the driving time Ti1 of the suction air amount adjusting means in idling operation and the suction air amount. The arrangement further includes a rate-of-flow characteristic correcting means 31, which makes a correction upon sensing the dislocation of the rate-of flow characteristic on the basis of the difference of the suction air amount from its target value, and a feedback correction value calculating means 36 which calculates the driving time Ti on the basis of the difference of the engine speed from its target value, the rate-of-flow characteristic, and the rate-of-flow characteristic correction value Ti2. The suction air amount adjusting means is driven in accordance with the actual rate-of-flow characteristic at the present.