TRANSFORMER DEVICE

Two wire materials for coils can be efficiently processed into the same winding state and a configuration in which various characteristics and a cost thereof fall within a predetermined range is formed. Provided is a transformer device to be mounted in a LAN for networking, in which a wire material 11A for a primary coil and a wire material 11B for a secondary coil are wound around an annular core 31 to allow a signal component to pass from the wire material 11A for the primary coil to the wire material 11B for the secondary coil, wherein the wire material 11A for the primary coil is formed of a one-layer insulating wire material, and the wire material 11B for the secondary coil is formed of a three-layer insulating wire material, respectively, and the wire materials are wound around the core 31 in the form of a twisted wire (11) formed by intertwisting two insulating wire materials 11A and 11B.