A steering mechanism 1 is configured as a steering mechanism which allows an arbitrary relationship to be set between a steering mechanism unit 2 through which steering of a driver is input and a turning mechanism unit 3 for turning wheels 5, 5 to be turned, those units being controlled by an ECU 30 on a steer-by-wire basis. When alarm control to wake up the driver is performed according to a determination indicating a reduction of the wakefulness of the driver, the ECU 30 suspends the steer-by-wire control to control the turning mechanism unit 3 independently of the steering mechanism unit 2. As a result, even when an improper steering input is provided by the driver who is at a low level of wakefulness, it is possible to prevent such mis-steering from being reflected in driving.