To improve the control precision of fuel injection quantity by precisely setting an invalid pulse duration of driving signals for the fuel injection valve.

An opening period and a closing period of a valve element of a fuel injection valve are detected, the difference TTN between the delay Ta from an output start time of the injection pulse signal to the opening period and the delay Tb from an output finish time of the signal to the closing period is computed (S11-S20), the learned value TSO of the invalid pulse duration saved for every region of fuel injection valve driving voltage VB is searched, the weighted average of the difference TTN and the learned value TSO is calculated to give a learned value TS of a new invalid pulse duration, and the learned value TSO is renewed with the leaned value TS.