To make it possible to obtain the optimal position of a detent portion regardless of the inside diameter of a coil by making the thickness of a detent torque generating member completely negligible.

A stator includes: a stator base 2 constructed of a printed wiring board added to a magnetic bracket 1 with a shaft supporting portion disposed in its center; multiple air-core armature coils 3 placed on the stator base; and a drive circuit member D placed on the stator base so that it is not superposed on the air-core armature coils. The stator base has a center through hole disposed at the shaft supporting portion and through holes 2b formed outside the center through hole in the radial direction. Detent torque portions 1b formed by integrally pushing and raising the magnetic bracket 1 are housed in these through holes so that they are fit within the thickness of the stator base.