Abstract: A method suited for producing a conductor circuit board having a high-density, fine circuit pattern. Conductor circuits and dummy circuits are formed on the surface of a planar, electrically conductive substrate, and after removing a resist mask, unnecessary dummy circuits are removed. A thin metal film is formed over the surface of the conductive substrate and the surfaces of the conductor circuits and remaining dummy circuits. An insulating substrate is superposed on the surface of the conductive substrate on which the thin metal film is formed, and the two substrates are pressure-bonded together with heat applied thereto. Subsequently, only the conductive substrate is removed, and exposed portions of the thin metal film are removed by etching.