PURPOSE: To reduce generated eddy current loss by individually and electrically insulating plurality of pillar conductors having the rectangular cross-section, forming a winding with the layer formed with these conductors integrated through bundling with the common insulator and by forming a winding with such conductors twisted for 90° at the specified position in the course of such winding.

CONSTITUTION: The width in the X direction and the width in the Y direction are respectively determined and pillar conductors 4 are provided with the wire insulator 5a. Thereafter, these conductors are bundled and integrated using the common insulator 5b, thus forming a layer. A pair of these layers providing the common insulators are placed in parallel in the X axis direction at the edge of coil where the leaked magnetic flux in the X axis direction becomes larger than that in the Y axis direction, namely at the internal and external circumferences of coil. These layers are twisted by 90° for the coil center in order to form a coil.