To reduce the HC in the exhaust gas, especially the HC at the starting time, by calculating the HC density in the exhaust gas, and the HC exhaust amount from a fuel injection amount or a suction air amount, and regulating the fuel injection amount or the suction air amount, according to the comparing result of the above HC exhaust amount with a specific value.

An O2 feedback control means 201 in an ECU carries out the O2 feedback, while a basic fuel injection amount operation means 202 operates the basic fuel injection amount from a flow-in air amount. And a rotation variation operation means 203 operates the variation of the engine rotation, and decides a fuel injection amount correcting amount to make the above rotation variation less than a specific value. Furthermore, the HC exhaust amount is operated from the signal of an HC sensor by an HC exhaust amount operation means 205, and the fuel injection amount and the correcting amount of the throttle opening are decided to make the HC exhaust amount less than a specific value by a fuel injection amount and throttle opening correcting value operation means 206.