PURPOSE: To uniformalize real injection quantities of fuel by means of respective injection valves so as to improve idle stability and the like and reliability by detecting delay times for closing respective injection valves, making compensatory control of the injection quantities of respective injection valves based thereon.

CONSTITUTION: One end side of an intake pipe 25 connected to the intake side of an engine body 21 is formed in four branched pipes 25A, and on respective pipes 25A, injection valves 1A-1D are mounted so that fuel is injected toward the insides of cylinders 22A-22D. In this case, respective oscillation sensors 30 serving as delay times detection means are provided in the injection valves 1A-1D. On the other hand, the input side of a control unit 37 is connected to respective oscillation sensors 30 and its output side is connected to the injection valves 1A-1D. Respective injection quantities are compensated individually based on the delay times for closing respective injection valves 1A-1D.