A SnO.sub.2 film having a prescribed pattern feature is formed on a substrate by a wet film-formation technology (e.g., sol-gel method). A Ni film is formed on the SnO.sub.2 film by an electroless plating method. The electroless plating method is conducted in the presence of at least one sulfur-containing compound selected from the group consisting of thiosulfates, thiocyanates and sulfur-containing organic compounds.