To obtain a multilayer air-core coil, suitable for the antenna coil or the like of an IC card by a method wherein the coil is reduced by a thickness of one conductor wire component by leading out both terminals of a conductor wire from the innermost peripheral layer of the coil and reduction in the thickness of the coil can be contrived.

A conductor wire 15 of a length required for winding a multilayer air-core coil is stored in a wire storage part 13 and thereafter, with one end of the conductor wire 15 fixed on a first wound core 11, the other end of the wire 15 is fixed on a second wound core 12 and the wound cores 11 and 12 are rotated in the opposite direction to each other in a state that an elastic force is applied to both ends of the wire 15 by the storage part 13, whereby the multilayer air-core coil is formed into a constitution, wherein both terminals of the wire 15 are led out from the innermost peripheral layer of the air-core coil.