PURPOSE: To maintain supercharging efficiency by a pressure wave supercharger and the combustibility of an engine desirably, and secure reliability in engine operation at the failing time of a fuel system.

CONSTITUTION: An engine with a pressure wave supercharger is provided with a pressure wave supercharger 8, a starting valve 7 provided near a connecting part downstream of a by-pass passage 13 by-passing the pressure wave supercharger 8 and constituted in such a way as to open an intake passage 11 receiving supercharging pressure only in a region where the supercharging pressure is the specified value or higher, and an electronically controlled fuel injection pump 20. In this case, a throttle valve 9 controlled in its opening interlockingly with the operation of an accelerator pedal 10 is disposed between the engine and the pressure wave supercharger fitting position of the intake passage 11.