PURPOSE: To prevent excess setting of a fuel supply rate which can take place on account of a reverse flow quantity of in take air during deceleration by setting a cylinder volumetric efficiency based on an aperture area of an engine intake air system, and an engine speed and setting the regulated rate of basic fuel supply rate according to the cylinder volumetric efficiency.

CONSTITUTION: A means A directly detects an intake air rate of an engine upstream of the compressor of a super charger, and a means B detects an engine speed. Further, a means C sets a basic fuel supply rate to the engine based on detected values of the intake air rate and the engine speed, and a means D controls fuel supply to the engine based on the basic fuel supply rate. Meanwhile, a means E detects an opening area of an engine intake air system which is variably controlled, and a means F sets a regulated rate of the basic fuel supply rate according to a cylinder volumetric efficiency set on the basis of the opening area and the engine speed in the engine intake air system. And then, a means G forcibly restricts the fuel supply rate, which is set by the means C when a deceleration operation state of the engine is detected by means H, to be within the restricted rate by the means F.