An object is to improve the combustion condition in an internal combustion engine equipped with a supercharger and performing diesel combustion using fuel having a relatively high self-ignition temperature in an operation state in which the engine load is increased or decreased. A control apparatus performs first injection during the compression stroke, causes spray guide combustion to occur, and starts to perform second injection at such a second injection time that combustion of injected fuel is started by flame generated by the spray guide combustion, thereby causing self-ignition and diffusion combustion of fuel to occur. During a response delay period in changing the boost pressure when changing the engine load of the internal combustion engine to a target engine load, the ratio of the quantity of fuel injected by the first injection to the total fuel injection quantity in one combustion cycle is made higher than the ratio of the quantity of fuel injected in the first injection to the total fuel injection quantity in one combustion cycle during the time when the engine load is equal to the target engine load and the actual boost pressure is equal to a target boost pressure corresponding to the target engine load.