The present invention is to provide a plurality of unit coil portions formed by winding one conductive wire about a winding axis is placed side by side in the winding axis direction, each of the unit coil portions is formed by unit wound portions having different inner circumferential lengths from each other, the unit coil portion is multi-layered in at least a part thereof by pushing at least a part of the unit wound portion having a small inner circumferential length inside the unit wound portion having a large inner circumferential length, and the unit wound portion is wound along a loop shape winding route having a plurality of arc shape corner parts. In unit wound portions forming the unit coil portion, corner parts formed at the same phase angle with respect to the winding axis are formed in an arc shape having curvature center at the same position.