Under a state where a steering motor (22) is stopping, an ECU (45) for checking controls an electromagnetic clutch (31) to a disconnected state at step (S11), and inputs a steering angle and a steering torque (T) at step (S12). At step (S13), a decision is made whether the steering torque (T) is below a target torque (To) or not, and the control goes to step (S14) if the torque (T) is below the torque (To). An abnormality flag (MFB) is set at ''0'' indicative of normal state of the clutch (31). If the torque (T) is larger than the torque (To) at step (S13), the control goes to step (S15), and the flag (MBF) is set at ''1'' indicative of abnormal state of the clutche (31). Judgment of abnormality is performed when the steering angle is below a predetermined steering angle (o) by processing at step (S16).