A producing method of a wired circuit board includes the step of preparing a wired circuit board including an insulating layer and a conductive pattern having a wire covered with the insulating layer and a terminal portion exposed from the insulating layer; and the step of forming a semiconductive layer on a surface of the insulating layer by dipping the wired circuit board in a polymeric liquid of a conductive polymer in which an electrode is provided, and applying a voltage so that the electrode becomes an anode and the conductive pattern becomes a cathode.