Abstract: A SnO2 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 SnO2 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.

Abstract: A method of circulating an electroless nickel plating solution is characterized in that the system comprises the following process steps effected in the following order: (A) a step of electrolessly plating nickel using a plating solution having nickel hypophosphite contained as a chief chemical material for supplying a plating metal ion Ni2+ and a hypophosphorous acid ion H2PO2− acting as a reducing agent; (B) a step of removing HPO32− from a plating solution that has aged in the step (A); (C) a step of desalting the mother liquor separated from the step (B); and (D) a step of adjusting the components of the treated plating solution and then circulating same back into the step (A) of electroless nickel plating. According to the present invention, the plating solution is free from the formation and accumulation of a sulfuric acid salt and hence a long service life is ensured and a great advantage in environmental protection is provided.