A producing method of a wired circuit board includes the steps of preparing a two-layer base material including a metal supporting layer and an insulating layer, covering an upper surface of the insulating layer and respective side end surfaces of the insulating layer and the metal supporting layer with a photoresist, placing a photomask so as to light-shield an end portion and a portion where a conductive layer is to be formed of the upper surface, exposing to light the photoresist covering the upper surface from above the photoresist via the photomask, exposing to light the photoresist covering the respective side end surfaces from below the photoresist, forming an exposed portion of the photoresist into a pattern by removing an unexposed portion thereof to form a plating resist, and forming an end-portion conductive layer and the conductive layer.