To wind a coil with high density, make the final height of the coil low, reduce the size, and prevent the lowering of a motor characteristic by forming guide grooves for guiding the coil, on the base end side of the teeth of a back yoke.

A stator core 51 is provided with a cylindrical back yoke 51a and a plurality of teeth 51h, formed protruding toward the internal peripheral side from the back yoke 51a. Also on the base end side of the teeth 51b of the back yoke 51a, guide grooves 51c are formed. The winding for a coil 52a is begun from a lead-wire side end part, causing it to fit into a guide groove 51c, wound up to the opposite lead-wire side end part, and returns to the lead- wire side end part. As a result of this, coil 52a elements become parallel on the lead-wire side end side and do not cross one another. Consequently, the lead-wire-side end side height H1 of the coil section 52 becomes low. Meanwhile, coil 52a elements cross on the opposite-lead-wire side end side. Accordingly, the height H1 can be made lower than an opposite-lead-wire side end side height H2.