To simply and precisely absorb a step difference of generated torque between cylinders.

A deviation or a ratio a cylinder pressure integrated value in a specified crank angle region after a compression a top dead center and a cylinder pressure integrated value in a specified crank angle region before the compression top dead center is computed as a parameter to show generated torque of each cylinder by detecting cylinder pressure for each of the cylinders. Thereafter, the generated torque for each of the cylinders and an average value of all the cylinders are compared (S22, S24), ignition timing is corrected to spark advance for the cylinder generated torque of which is smaller than the average value (S23) and ignition timing is corrected to delay for the cylinder generated torque of which is larger than the average value (S25).