An electronic control throttle body has a default mechanism for securing the self-propelling of a vehicle at the time of faulty. A throttle control unit controls the position of a throttle valve by using a motor on the basis of a target throttle valve opening degree obtained by an engine control unit. In this respect, when the target throttle valve opening degree inputted from the engine control unit crosses over a default opening degree f0 of a default mechanism, an integration value having been added is set to 0, and an integration value having been calculated hereinafter is added to the set value to thereby perform a feedback control.