To control an air-fuel ratio in a cylinder to be a proper value by suppressing the deviation of the air-fuel ratio due to the back flow of secondary air.

This control device 10 for an internal combustion engine comprises a valve position determining part 41 for determining whether a timing for opening an exhaust valve is before the first bottom dead center after an ignition top dead center or not, an injection timing determining part 42 for determining the injection timing for the secondary air to inject the secondary air after a value preset in accordance with the operated conditions of the internal combustion engine passes through the bottom dead center when the timing for opening the exhaust valve is before the bottom dead center and to inject the secondary air after the timing for opening the exhaust valve when the timing for opening the exhaust valve is after the bottom dead center, and an injection control part 43 for injecting the secondary air into an exhaust passage of the internal combustion engine at the determined injection timing for the secondary air.