A mounting device in which a conductive film that is not separated is formed on a resin substrate. Alloy thin films, which contain more than 50% by atom of Cu, 5% by atom or more and 30% by atom or less of Ni, and 3% by atom or more and 10% by atom or less of Al, are formed on a base consisting of a resin so as to be brought into contact with a surface of the base by sputtering. Conductive films consisting of copper are formed on surfaces of the alloy thin films so as to obtain a wiring film having a two-layer structure and a metal plug filled in a connection hole. The alloy thin films have high adhesion to a resin; and hence, the wiring film and the metal plug are not separated.