To provide a method and a device for controlling the action of a multi-phase motor, especially for rotating a motor from inactive state to operable state.

The electrical properties of one or more pieces of phase winding are detected initially by executing, for example, induction detecting action. It is determined whether the rotor of a motor is rotating, using the detected values of the electrical properties. When it is determined that the rotor is not rotating, spin up action is executed to put the rotation of the rotor at operable rotational speed. On the other hand, when it is determined that the rotor is rotating, resynchronizing action is executed so as to synchronize the application of a drive signal for the phase winding of a motor with the dynamic position of the rotor.