In an inductive element which is intermittently excited by a boosting opening and closing element and charges a high-voltage capacitor to a high voltage, an inductive element current proportional to a voltage across both ends of a current detection resistor and a boosted detection voltage which is a divided voltage of the high-voltage capacitor are input to a boosting control circuit portion via a high-speed A/D converter provided in an arithmetic and control circuit unit. The boosting control circuit portion adjusts the inductive element current so as to be suitable for the time from the present rapid excitation to the next rapid excitation, and controls opening and closing of the boosting opening and closing element so as to obtain a targeted boosted high voltage which is variably set by a microprocessor of an arithmetic and control circuit unit.