The present invention provides technology for noble metal plating of titanium surfaces. A process such as the following would be carried out when manufacturing a partially gold-plated separator for a fuel cell, for example. First, a titanium component made of titanium or titanium alloy is prepared for use as the fuel cell separator (S10). This titanium component is a titanium component whose surfaces are coated with carbon-containing substance. This titanium component is then subjected to a first heat treatment at a prescribed first temperature of between 300 and 700 degrees Celsius (S20). Gold plating of the surfaces of the heat-treated titanium component is then carried out (S80). In this way it is possible to more easily carry out gold electrolytic plating of titanium surfaces.