PURPOSE: To mitigate torque shock generated at reopening fuel supply after stopping fuel supply at a decided decelerating operation.

CONSTITUTION: When fuel injection for two cylinders is stopped at a decided decelerating operation from usual four cylinders injection in a four-cylinder internal combustion engine 1, the ignition timing is delayed by a decided angle control quantity FCADV1, and thererafter when all four cylinders are stopped, it is further delayed by a decided delay angle control quantity FCADV2. Next, when fuel supply for two cylinders is reopened, the delay angle control quantity FCADV2 is set as the initial value and gradually decreased to zero in a decided time, and when injection for all four cylinders is reopened, the delay angle control quantity FCADV1 is set as the initial value and gradually decreased to zero in a decided time. Thus, increase of torque is restrained by the delay angle control at reopening fuel supply, and torque shock is mitigated.