PURPOSE: To enable to control an engine in a reliable and smooth manner even if current driven type injectors are used for the control of fuel injection, by preventing erroneous judgemenr of electromagnetic noises produced at the time of driving the injectors as a knock signal in a reliable manner.

CONSTITUTION: At a step 305, a period T before starting of a knock judging period is detected from an angle signal N3 produced one step before the knock judging period. In case that it is detected at a step 306 that the injection period of injectors is smaller than T, the process proceeds to a step 311 and fuel is injected by energizing the injectors in synchronism with the angle signal N3 produced by a rotational angle sensor. That is, operation for fuel injection is terminated before starting of the knock judging period. In case that τ is greater than T and τ is greater than t+T, the process proceeds to the step 311 and the injectors are energized by the angle signal N3. On the other hand, in case that T+t is greater than τ, the process proceeds to a step 308. In case of YES at the step 308, the process proceeds to a step 309 and the injectors are energized in synchronism with an angle signal N2. In case of NO at the step 308, on the other hand, the process proceeds to a step 310 and the injectors are energized in synchronism with an angle signal N4.