A control device is provided that acquires an estimated value of a waste gate valve opening, derives a first relation which is established between a throttle downstream pressure and an intake valve flow rate based on the estimated value, and derives a second relation which is established between the throttle downstream pressure and the throttle flow rate from a throttle model based on a measured value of a throttle opening and a measured value of a throttle upstream pressure. Subsequently, the control device calculates an estimated value of the intake valve flow rate based on the first relation and the second relation, and regulates a correspondence relation of the estimated value of the waste gate valve opening and the manipulated variable of the waste gate valve based on a comparison result of the estimated value of the intake valve flow rate and a measured value of an intake flow rate.