To reduce pumping loss of an engine in speed reduction.

A fuel cut is performed by making final fuel injection quantity FP as zero, while engine speed Ne is reduced from Ne2 to Ne1. By substantially opening an EGR valve completely, pumping loss is reduced, while opening TV1 for opening a throttle valve slightly is set during a prescribed period T1 from the fuel cut. By fully opening a swirl valve and introducing air up to a degree, without lowering a catalyst temperature, exhaust of non-discharged EGR gas is accelerated.