Tungsten oxide photocatalyst and method for producing tungsten oxide photocatalyst

The disclosed tungsten oxide photocatalyst (100) has: a substrate (101); a tungsten oxide thin film (102) formed on the surface of the substrate (101); and a catalyst promoter (103) selected from at least one metal represented by the chemical symbols Pt, Pd, Rh, Au, Ru, Cu, Ir, Ni, and Ag. The tungsten oxide thin film (102) is a thin film formed by means of gas flow sputtering, and the particulate catalyst promoter (103) is supported at the surface of the tungsten oxide thin film.