state the heat exchanger 43 and the intake passage 17 communicate with each other via the egr passage 42 when the third opening and closing valve v 3 is in the closed state communication between the heat exchanger 43 and the bridge passage 41 is blocked when the third opening and closing valve v 3 is in the open state the heat exchanger 43 and the joining passage 23 ad communicate with each other via the egr passage 42 and the bridge passage 41 the second opening and closing valve v 2 serves as a second opening and closing device that is provided downstream of the heat exchanger 43 in the egr passage 42 to open and close the egr passage 42 the third opening and closing valve v 3 serves as a third opening and closing device that is upstream of the heat exchanger 43 to open and close the egr passage 42 the control computer c controls opening and closing of the first opening and closing valve v 1 the second opening and closing valve v 2 and the third opening and closing valve v 3 fig3 is a region graph represented by the rate of revolution n of the engine and engine load f a region g 1 is a region where it is desirable that a turbine driving force in the turbocharger type supercharger 19 is.