Abstract: A stratified internal combustion engine has a trap chamber for a rich mixture having suction and discharge apertures communicating the trap chamber with the main combustion chamber. A separating wall is provided between the suction and discharge apertures and also a fuel injection nozzle is arranged, as a means to trap the rich mixture in said trap chamber, for supplying fuel to said suction aperture by discharging the fuel at a pressure higher than atmospheric pressure when an intake valve is opened, for thereby facilitating the introduction of the rich mixture into the trap chamber and scavenging the residual gases in the trap chamber and improving the trapping effect of the trap chamber with a resultant improvement in stratified combustion in the engine.