Internal combustion engine

An internal combustion engine characterized by being provided with fuel injectors which enable high pressure fuel to be directly injected into combustion chambers of the engine, spark plugs which are provided in the combustion chambers, a catalytic converter provided in the middle of the exhaust pipe for purifying the exhaust, a temperature sensor for detecting the temperature of a catalyst of the catalytic converter and a control unit which receives as input the engine rotational speed, load, and the detection value of the catalyst temperature sensor for controlling the engine, where, when the temperature of the catalyst is lower than a predetermined target temperature, the fuel injectors inject additional fuel into the combustion chambers under the instruction of the control unit during at least one of the expansion and the exhaust strokes to mix it with the exhaust and wherein the internal combustion engine includes means for reigniting and burning the mixture of exhaust and additional fuel upstream of the catalytic converter so as to heat the catalyst to the target temperature.