PURPOSE: To implement a proper fuel cut according to the condition of the engine load only through the suction pipe pressure.

CONSTITUTION: When the engine speed NE is not less than the set value NCUT, examination is made whether or not an air-conditioner is in the operating condition (S202), and when the air-conditioner is operated, examination is made whether or not the suction pipe pressure PM is larger than the fuel cut release judgement pressure FRA (S203). In the case of PM≤FRA, examination is made whether or not the suction pipe pressure PM is not greater than the fuel cut judgement pressure FCA (S204), and in the case of PM≤FCA, a judgement is made that the fuel cut condition when the air-conditioner is under operation is met, and the fuel cut flag FCUT is set (S207). When the air-conditioner is under operation, the inconvenience that the fuel cut is difficult to be implemented is avoided beforehand due to the larger value of the fuel cut judgement pressure, and the reduction of the exhaust emission, the improvement of the fuel consumption or the like are achieved. And, the fuel cut judgement is made according to the engine load only by the suction pipe pressure PM, making it unnecessary to provide a sensor to detect the throttle valve opening and improving the reduction of the system cost.