PURPOSE: To reduce an eddy current loss and to improve driving efficiency by laminating a plurality of thin plates to form a yoke in which a coil is wound, and securing an armature in which pole teeth are formed on the upper surface of the yoke.

CONSTITUTION: A stator 2 is formed of a yoke 11, a coil 12, an armature 13 and a permanent magnet 16. The yoke 11 is formed by laminating a plurality of thin plates molded in the same shape, and the magnet 16 is held by the two yokes 11 therebetween. An armature 13 in which pole teeth 33 are formed previously by cutting at four positions opposed to the poles of the yokes 11 on the upper surface of the flat plate is placed on the yoke 11 and secured. Thus, an eddy current loss when the coil is driven is reduced to improve its driving efficiency. Since the teeth are formed on the armature of separate member from the yoke, machining accuracy is improved, and its yield is improved by forming the teeth corresponding to the plurality of armatures on the single material.