When a stepping motor is driven to rotate by a main driving pulse, if an induced signal exceeding a reference threshold voltage is detected only in a third segment, a pulse down operation is performed, and the main driving pulse is not changed when the same is detected in at least a first and the third segments. When it is detected only in a second and the third segments, a rank-up is performed without performing the driving by a correction drive pulse and, when it is not detected in at least the third segment, the rank up operation is performed after the driving by the correction driving pulse.