Disclosed is a photocatalyst which is excited when irradiated with visible light and exhibits high photocatalytic activity stably. This photocatalyst has a white hue with little yellow tint. Specifically, titanium oxide particles and a halogenated platinum compound are heated and mixed in a liquid medium, so that the surfaces of the titanium oxide particles are loaded with the halogenated platinum compound; then the pH of the liquid medium is adjusted to 5 or less; and after that, the liquid medium is neutralized if necessary. By such a process, there can be produced a photocatalyst having a specific surface area of 10-100 m.sup.2/g, wherein the surfaces of the titanium oxide particles are loaded with the halogenated platinum compound and the b* value of the powder color according to the Hunter color system is not more than 6.