According to the present invention, if a required power generation signal is supplied while a vehicle is decelerated in a fuel-efficiency-oriented control mode, an electrically-operated waste gate valve is operated so that opening of the electrically-operated waste gate valve is increased as the required power generation amount increases. Then, if it is determined that the vehicle is decelerated on the basis of accelerator opening and a vehicle speed, and fuel is cut off, an electronically controlled throttle valve is operated toward a fully opened side. In addition, if any one of following conditions is satisfied: the fuel-efficiency-oriented control mode is not selected; there is supply of a required output signal; and the vehicle is not decelerated, opening of the electrically-operated waste gate valve is adjusted so that output torque of an engine becomes a required output value.