An internal combustion engine provided with double system of fuel injection, comprising: a direct injection injector; a port fuel injection injector; an engine operating condition detection unit for detecting engine operating condition; a fuel injection quantity control unit for monitoring the engine operating condition and controlling respective fuel injection quantity of the direct injection injector and the port fuel injection injector depending on the engine operating condition; a memory unit incorporated with four sheets of ignition timing maps including a first ignition timing map allocated on the basis of the engine operating condition so that the ignition timing of the engine at the fuel injection using only the direct injection injector substantially accords with the maximum torque generation timing, a second ignition timing map allocated on the basis of the engine operating condition so that the ignition timing of the engine at the fuel injection using only the direct injection injector substantially accords with the knocking limit torque generation timing, a third ignition timing map allocated on the basis of the engine operating condition so that the ignition timing of the engine at the fuel injection using only the port fuel injection injector substantially accords with the maximum torque generation timing, and a fourth ignition timing map allocated on the basis of the engine operating condition so that the ignition timing of the engine at the fuel injection using only the port fuel injection injector substantially accords with the knocking limit torque generation timing; and an ignition timing control unit for controlling the ignition timing of the cylinder by using a ratio of fuel injection quantity of the direct injection injector and the port fuel injection injector and the four sheets of the ignition timing maps. a direct injection injector; a port fuel injection injector; an engine operating condition detection unit for detecting engine operating condition; a fuel injection quantity control unit for monitoring the engine operating condition and controlling respective fuel injection quantity of the direct injection injector and the port fuel injection injector depending on the engine operating condition; a memory unit incorporated with four sheets of ignition timing maps including a first ignition timing map allocated on the basis of the engine operating condition so that the ignition timing of the engine at the fuel injection using only the direct injection injector substantially accords with the maximum torque generation timing, a second ignition timing map allocated on the basis of the engine operating condition so that the ignition timing of the engine at the fuel injection using only the direct injection injector substantially accords with the knocking limit torque generation timing, a third ignition timing map allocated on the basis of the engine operating condition so that the ignition timing of the engine at the fuel injection using only the port fuel injection injector substantially accords with the maximum torque generation timing, and a fourth ignition timing map allocated on the basis of the engine operating condition so that the ignition timing of the engine at the fuel injection using only the port fuel injection injector substantially accords with the knocking limit torque generation timing; and an ignition timing control unit for controlling the ignition timing of the cylinder by using a ratio of fuel injection quantity of the direct injection injector and the port fuel injection injector and the four sheets of the ignition timing maps.