To provide an internal combustion engine capable of uniforming exhaust gas pressure in an assembly section of exhaust gas ports and that in other exhaust ports in a structure with a part of a plurality of the exhaust gas ports assembled at one place in a cylinder head.

In this internal combustion engine, a part of the exhaust gas ports (hereinafter referred to as the assembly exhaust gas port) 213 out of the plurality of the exhaust gas ports 213, 214 is assembled in the cylinder head 21, and the assembly section of these assembly exhaust gas ports 213, 213 and other exhaust gas ports (hereinafter referred to as independent exhaust gas ports) 214 are respectively connected to the outside the cylinder head 21. When an amount of increase in a fuel for decreasing an exhaust gas temperature is referred to as an increase fuel, the amount of injection of the increase fuel injected in a combustion chamber 211 on the independent exhaust gas port 214 side is set to be less than that injected to the combustion chamber 211 on the assembly exhaust gas port 213 side.