In a wiring board wherein an opening is defined at a predetermined position of a film-like insulating substrate, an electric wiring provided with a connection terminal covering the opening is disposed on a principal plane of the insulating substrate, and a conductive member to be connected with the connection terminal of the electric wiring is disposed inside the opening; the conductive member having a thickness from a surface on which the electric wiring of the insulating substrate has been disposed is thinner than that of the insulating substrate.