To provide an engine capable of improving the transient characteristic of a multistage supper charge system.

An engine 1 is provided with a multistage super charge system 2 including a high pressure stage turbocharger 4 and a low pressure stage turbocharger 3 and is provided with a standard cylinder 11A connected to the high pressure stage turbocharger 4 at the exhaust side, an EGR cylinder 11B connected to any one of an EGR passage 13 and the low pressure turbocharger 3 at the exhaust side, a switching valve 15 for switching the connection of the EGR cylinder 11B and an ECU 20 for controlling the switching valve 15. When the ECU 20 determines that the operation condition of the engine is in a transition state, the exhaust side of the EGR cylinder 11B is connected to the low pressure stage turbocharger 3.