PURPOSE: To form multi-layered coils orderly and regularily by a method wherein the coil winding sections of a core are provided with projections while coils are wound between the projections.

CONSTITUTION: A core 22 is provided with a plurality of projections 26 while coils 30 are formed between these projections 26. The projections 26 are preferably projected into the lateral direction with respect to the coil winding sections of the core 22 which are extended radially or circumferentially. The projections 26 can be formed integrally with the core 22 or can be formed by mounting members, constituting the projections, on the core 22 while the height thereof can be set in accordance with the height of the layer of the coil 30. The projections 26 can be provided symmetrically at both sides of the core 22 by a proper number. The coils 30 are formed on the straight parts of the core 22 between the projections 26. According to this method, the coils 30 consisting of multi-layered windings are formed orderly and regularily.