To solve such a problem that a conventional chemical adsorption film cannot be formed on the surface of a precious metal such as gold and platinum which do not contain active hydrogen on the surfaces of the base materials, because of using only a chemical bond between an adsorbent and the active hydrogen on the surface of the substrate.

The method for manufacturing a precious metal product having water repellency, oil repellency and antifouling properties includes the steps of: forming the first film on the surface of a precious metal of a substrate by using a triazine thiol compound or a thiol compound, which contains an alkoxysilyl group, an amino group or a carboxyl group; and forming a second film thereon by bringing the surface of the precious metal into contact with a composite-film-forming solution which has been prepared through mixing a substance that contains a fluorocarbon group, a hydrocarbon group and a chlorosilyl group as a main component and a substance that contains the chlorosilyl group as a main component and diluting them with a non-water-based organic solvent, in a dry atmosphere, and by reacting them in the dry atmosphere.