PURPOSE: To prevent a rotor tooth from returning and allow it to stop as it is, even when the rotor tooth goes beyond a stator tooth after a drive current is stopped, by tapering at least one point end side of either the rotor tooth or the stator tooth of a hybrid step motor.

CONSTITUTION: A rotor 1 is formed of a permanent magnet 2 and magnetic materials 3, 4 provided in the periphery of this permanent magnet. When the rotor, in which many teeth 3a, 4a are formed in peripheral sides of the magnetic materials 3, 4, arrives at a predetermined position, a current is cut off, when the tooth 3a of the rotor 1 is rotated by its inertia in a direction of a arrow mark relating to a predetermined tooth 12a of a stator 9 and stopped to go a little beyond the tooth of the stator. Since the tooth 3a of the rotor 1 is tapered in proportion as in a tooth point part where roundness is provided, a flow of magnetic flux in the tooth 12a from this tooth 3a disappears, and the tooth 3a is opposed to the tooth 12a and left stationary as it is without returning a little.