is supplied to the intake manifold 4 during the operation of the engine e an electronically controlled throttle valve 22 is provided in the intake pipe 3 to adjust the intake flow rate of the engine e in a prescribed operating range between the intake pipe 3 and intake manifold 4 is provided with a swirl control valve 23 for increasing the intake flow velocity by restricting the cross sectional area of the flow passage in a low rpm low load operating condition the intake pipe 3 is also provided with an intake flow rate sensor 24 for detecting a flow rate upstream of the vg turbo 21 and a boost pressure sensor 25 is provided downstream of the vg turbo 21 to detect the boost pressure the throttle valve 22 is provided with a throttle valve opening sensor 26 for detecting the opening angle of the throttle valve 22 the swirl control valve 23 is connected to the exhaust manifold 5 via an exhaust gas recirculation egr passage 31 to conduct high temperature exhaust gas to the combustion chamber the egr passage 31 includes a cooler passage 31 a and a bypass passage 31 b that bifurcate from a switching valve 32 provided at an exhaust end thereof and an egr valve 33 provided at an intake end thereof for adjusting the amount of the exhaust gas egr gas that flows into the combustion chamber is provided at a point where the two.