A control apparatus for an internal combustion engine comprising: a fuel injection valve that injects fuel radially from a location near the center of a combustion chamber of the internal combustion engine; an ignition device whose position relative to said fuel injection valve is set in such a way that a part of a fuel spray injected through said fuel injection valve passes through an ignition-capable region and the ignition device can ignite the fuel spray directly; and combustion control means that is configured to perform pre-injection through said fuel injection valve at a pre-injection time (Tp) during the compression stroke, ignites a pre-spray, which is a fuel spray formed by the pre-injection, by said ignition device, and starts to perform main injection through said fuel injection valve at a main injection time (Tm) after the ignition of said pre-spray by said ignition device and before the top dead center of the compression stroke that is set in such a way that combustion of the fuel injected by said main injection is started by a flame generated by ignition of said pre-spray and being present at the time when the main injection is started, thereby causing self-ignition of fuel to occur and causing at least a portion of the fuel injected by said main injection to be burned by diffusion combustion, wherein in at least a part of the operation range of the internal combustion engine, said combustion control means performs, while the flame is propagating, middle injection in addition to said pre-injection and said main injection in one combustion cycle at a middle injection time (Tmid) after the ignition of said pre-spay by said ignition device and before said main injection time (Tm) to inject a quantity of fuel (Smid) smaller than the quantity of fuel (Sp) injected by said pre-injection in the same combustion cycle through said fuel injection valve, thereby causing the fuel injected by said middle injection to be burned by propagation of flame starting from flame generated by the ignition of said pre-spray, wherein said part of the operation range is an operation range in which the engine load of the internal combustion engine is higher than a predetermined load, and said combustion control means performs said pre-injection and said main injection in one combustion cycle in the operation range in which the engine load of the internal combustion engine is lower than or equal to said predetermined load and performs said middle injection in addition to said pre-injection and said main injection in one combustion cycle in the operation range in which the engine load of the internal combustion engine is higher than said predetermined load. a fuel injection valve that injects fuel radially from a location near the center of a combustion chamber of the internal combustion engine; an ignition device whose position relative to said fuel injection valve is set in such a way that a part of a fuel spray injected through said fuel injection valve passes through an ignition-capable region and the ignition device can ignite the fuel spray directly; and combustion control means that is configured to perform pre-injection through said fuel injection valve at a pre-injection time (Tp) during the compression stroke, ignites a pre-spray, which is a fuel spray formed by the pre-injection, by said ignition device, and starts to perform main injection through said fuel injection valve at a main injection time (Tm) after the ignition of said pre-spray by said ignition device and before the top dead center of the compression stroke that is set in such a way that combustion of the fuel injected by said main injection is started by a flame generated by ignition of said pre-spray and being present at the time when the main injection is started, thereby causing self-ignition of fuel to occur and causing at least a portion of the fuel injected by said main injection to be burned by diffusion combustion, wherein in at least a part of the operation range of the internal combustion engine, said combustion control means performs, while the flame is propagating, middle injection in addition to said pre-injection and said main injection in one combustion cycle at a middle injection time (Tmid) after the ignition of said pre-spay by said ignition device and before said main injection time (Tm) to inject a quantity of fuel (Smid) smaller than the quantity of fuel (Sp) injected by said pre-injection in the same combustion cycle through said fuel injection valve, thereby causing the fuel injected by said middle injection to be burned by propagation of flame starting from flame generated by the ignition of said pre-spray, wherein said part of the operation range is an operation range in which the engine load of the internal combustion engine is higher than a predetermined load, and said combustion control means performs said pre-injection and said main injection in one combustion cycle in the operation range in which the engine load of the internal combustion engine is lower than or equal to said predetermined load and performs said middle injection in addition to said pre-injection and said main injection in one combustion cycle in the operation range in which the engine load of the internal combustion engine is higher than said predetermined load.