To improve peeling resistance of a platinum film and the wear resistance of the surface by impregnating nitrogen ison and carbon ions into the surface of a metallic product in this order, thereafter impregnating platinum ions therein, then forming a platinum film and subsequently impregnating platinum ions as well.

On the surface of a metallic product composed of stainless steel, cemented carbide or the like such as a die for press-forming a glass product, a platinum film is formed, and the surface is modified to improve its releasing properties and oxidation resistance. At this time, the surface of the metallic product is impregnated with platinum ions, thereafter, a platinum film is formed to a film thickness of about 0.1 to 0.5 μm, and moreover, platinum ions are impregnated therein. The ion impregnation is executed preferably in such a manner that the impregnating amt. is controlled to about 1 to 5×1015 ions/cm2, the accelerating voltage is controlled to about 10 to 200 kev, and the ion current is controlled to about 10 to 100 mA. In this way, the peeling resistance of the platinum film is improved. Moreover, it is preferable that, prior to the impregnation of the platinum ions, the metallic surface is impregnated with nitrogen ions and carbon ions as well to increase the strength of the base metal and to improve its wear resistance.