A target air amount for achieving a requested torque is calculated from the requested torque by using a virtual air-fuel ratio. The virtual air-fuel ratio is changed from a first air-fuel ratio to a second air-fuel ratio in response to a condition for switching an operation mode from an operation by the first air-fuel ratio to an operation by the second air-fuel ratio being satisfied. After the virtual air-fuel ratio is changed from the first air-fuel ratio to the second air-fuel ratio, a target air-fuel ratio is switched from the first air-fuel ratio to the second air-fuel ratio. After the virtual air-fuel ratio is changed from the first air-fuel ratio to the second air-fuel ratio, a target valve timing is switched from a first valve timing to a second valve timing.