A pair of disk-shaped guide members abut on opposite end surfaces in the axial direction of a conductor wire wound round into a coil shape by using a separable jig. The guide members are biased toward each other by engaging a part of the conductor wire with engaging portions formed at circumferences of the pair of guide members. Then, the jig is separated from the center of the conductor wire, thereby maintaining the coiled shape of the conductor wire to create a bobbinless coil having an exposed inner peripheral surface. In addition, the pair of disk-shaped guide members are biased toward each other by utilizing a part of the conductor wire, and therefore a special biasing member is not needed.