Abstract: A metal conductor layer is provided on at least one surface of a heat resistant base. The heat resistant base is peelable from the metal conductor layer. The heat resistant base is preferably a metal foil or a non-thermoplastic polyimide resin film. The metal conductor layer preferably includes a vapor deposition metal layer and/or a plating metal layer. The metal conductor layer preferably includes a metal layer (I) formed in an interface with the heat resistant base by vapor deposition, and at least one metal layer (II) formed on the metal layer (I) by vapor deposition or electroplating. At least one insulative film layer of a non-thermoplastic polyimide resin may be provided on the metal conductor layer.