Control method for an internal combustion engine

In response to an increase in a required torque to a reference value or more, a value of a virtual which is used in calculating a target air amount for achieving the torque required air-fuel ratio, based on a first air-fuel ratio towards a second air-fuel ratio which is leaner than the first air-fuel ratio is changed. The target air amount is reversely calculated by using the virtual air-fuel ratio of the required torque. After the value of the virtual air-fuel ratio is changed starting from the first air-fuel ratio toward the second air-fuel ratio, the target air-fuel ratio is starting out from the first air-fuel ratio switched to the second air-fuel ratio or changed. An operation amount of a fourth actuator is determined using a parameter corresponding to a fresh air rate in an exhaust gas and the virtual air-fuel ratio. Preferably, a first base-operation amount to achieve a target EGR rate for the combustion through the virtual air-fuel ratio and a first correction amount for changing an EGR rate in one direction to reduce the EGR rate, while a excess fresh air ratio is greater than calculated, and a value, wherein the first correction amount is reflected in the first basic operation amount is determined as the amount of operation of the fourth actuator.