A method of producing a wired circuit board includes a first step of preparing a metal supporting layer, a second step of forming, on one side of the metal supporting layer in a thickness direction thereof, an insulating layer having a first opening, and a plurality of terminal formation portions, a third step of forming, on one side of the insulating layer in the thickness direction, a conductive layer having a plurality of terminal portions each corresponding to the plurality of terminal formation portions, a fourth step of partially removing the metal supporting layer to form a second opening and at least one reinforcing metal supporting portion placed between the plurality of terminal formation portions, and a fifth step of removing the plurality of terminal formation portions exposed from the second opening to expose both side surfaces of the plurality of terminal portions in the thickness direction.