The trend of manufacturing smaller and lighter electrical appliances requires that we develop high frequency transformers. The skin and proximity effect from high frequency increases the AC resistance, thereby significantly decreases the efficiency of energy transformation. In order to reduce the energy loss from high frequency circuits, magnetic materials are mixed in the insulating varnish to develop an energy-efficient enameled wire (magnet-conducting enameled wire). By interrupting the magnetic lines of force around the copper wires, the skin and proximity effect can be eliminated.We are working on experiments to overcome the difficulties of high frequency effects and improve manufacturing skills to efficiently produce energy-efficient enameled wires. We hope these energy-efficient magnet-conducting enameled wires will be widely used in electrical appliances.