To provide a winding structure for realizing a slotless motor, having high performance, in a small size and at low cost.

The slotless motor includes a rotor, having a core and a winding fixed on a shaft in such a manner that the core has a circumferential surface-like side face, facing a field magnet and both end faces at both the sides of the shaft in the axial direction, and the winding having a plurality of segments on the side face and the end face of this core. The windings of a plurality of turns for constituting each segment of this winding are wound regularly and symmetrically on both sides, at the shaft as a center so that the respective turns do not crossed with each other. The segments of the windings are regularly disposed, in a direction parallel to the axis of the shaft at least on the side face of the core so as not to generate gaps between the windings of both the sides disposed symmetrically, and regularly disposed by swelling on the radial outside so as to avoid the shaft at the center of the end face on both the end faces of the core.