PURPOSE: To reduce the occurrence of cogging by connecting portions to be used as poles of the stator integrally so that the stator can have a continuous portion facing the rotor.

CONSTITUTION: On a stator, coil 2 is wound round at a predetermined position. A cylindrical rotor 3 can rotate around the rotary shaft as the center of rotation. Stator 1 has portions 1A and 1B facing the outer circumference of the cylindrical portion of rotor 3. Portions 1A and 1B act as poles (pole piece) when a DC voltage is applied to coil 2. Further, portions 1A and 1B that act as poles are connected to each other through portions 1C and 1D of stator 1 integrally. Portions 1C and 1D are installed so as to eliminate a gap prepared between portion 1A and portion 1B in the conventional stator As a result, stator 1 has a continuous portion facing all over the entire circumference at a substantially equal distance.