A method for manufacturing a non-contact power feeding coil that is useable in a non-contact power feeding system configured of at least one of each a power feeding coil and a power receiving coil (4, 4A), wherein the power feeding coil includes a coil, configured to conduct an AC current of a specific frequency, wherein the coil has an AC resistance value (Rac), and a core that forms a section of a circulating magnetic path, which is interlinked with the coil, wherein in the coil a wire has an insulating covering around a conductor and wherein adjacent turns of the wire are in contact with each other, wherein the method for manufacturing the non-contact power feeding coil comprises the steps of: calculating a relationship between a covering thickness (Ti) of the insulating covering and the AC resistance value (Rac) of the coil by using a simulation with the power feeding coil as a subject at the specific frequency, wherein the respective resistance value (Rac) is calculated at five covering thicknesses (Ti) while the diameter of the conductor is kept constant, to determine the influence of a proximity effect that occurs at the specific frequency between adjacent turns of the wire; forming the coil, and forming the core; wherein the covering thickness (Ti) of the insulating covering is set on the basis of the relationship between the covering thickness (Ti) of the insulating covering and an AC resistance value (Rac) of the coil, so that the AC resistance value (Rac) is a predetermined resistance value or less, wherein the covering thickness (Ti) of the insulating covering is set to be the highest of the covering thickness corresponding to the AC resistance value (Rac) and a predetermined minimum covering thickness, at which it is possible to ensure insulating performance between portions of the conductor, wherein the predetermined AC resistance value is chosen lower than the AC resistance value corresponding to the minimum covering thickness, at which it is possible to ensure insulating performance between adjacent wire turns. wherein in the coil a wire has an insulating covering around a conductor and wherein adjacent turns of the wire are in contact with each other, wherein the method for manufacturing the non-contact power feeding coil comprises the steps of: calculating a relationship between a covering thickness (Ti) of the insulating covering and the AC resistance value (Rac) of the coil by using a simulation with the power feeding coil as a subject at the specific frequency, wherein the respective resistance value (Rac) is calculated at five covering thicknesses (Ti) while the diameter of the conductor is kept constant, to determine the influence of a proximity effect that occurs at the specific frequency between adjacent turns of the wire; forming the coil, and forming the core; wherein the covering thickness (Ti) of the insulating covering is set on the basis of the relationship between the covering thickness (Ti) of the insulating covering and an AC resistance value (Rac) of the coil, so that the AC resistance value (Rac) is a predetermined resistance value or less, wherein the covering thickness (Ti) of the insulating covering is set to be the highest of the covering thickness corresponding to the AC resistance value (Rac) and a predetermined minimum covering thickness, at which it is possible to ensure insulating performance between portions of the conductor, wherein the predetermined AC resistance value is chosen lower than the AC resistance value corresponding to the minimum covering thickness, at which it is possible to ensure insulating performance between adjacent wire turns. calculating a relationship between a covering thickness (Ti) of the insulating covering and the AC resistance value (Rac) of the coil by using a simulation with the power feeding coil as a subject at the specific frequency, wherein the respective resistance value (Rac) is calculated at five covering thicknesses (Ti) while the diameter of the conductor is kept constant, to determine the influence of a proximity effect that occurs at the specific frequency between adjacent turns of the wire; forming the coil, and forming the core; wherein the covering thickness (Ti) of the insulating covering is set on the basis of the relationship between the covering thickness (Ti) of the insulating covering and an AC resistance value (Rac) of the coil, so that the AC resistance value (Rac) is a predetermined resistance value or less, wherein the covering thickness (Ti) of the insulating covering is set to be the highest of the covering thickness corresponding to the AC resistance value (Rac) and a predetermined minimum covering thickness, at which it is possible to ensure insulating performance between portions of the conductor, wherein the predetermined AC resistance value is chosen lower than the AC resistance value corresponding to the minimum covering thickness, at which it is possible to ensure insulating performance between adjacent wire turns.