The coupling coil structure, which is provided with a plurality of primary coils formed by winding a conductor wire and a plurality of secondary coils provided so as to generate mutual inductance with the plurality of primary coils and in which, among the plurality of primary coils, one primary coil is tapped at an intermediate portion thereof by another primary coil at right angles, is characterized in that, among the plurality of secondary coils, a secondary coil in mutual inductance with the one primary coil is constituted into a coupling coil by one conductor having a width at least the size in the axial direction of the primary coil.