A high-durability photocatalyst film that is a laminated film comprising a substrate film and a photocatalytically active material layer formed thereon via a protective layer, wherein the substrate film is a film having specific performances in a weather resistance test with a sunshine weatherometer, the protective layer is an organic-inorganic composite graded film and the above laminated film exhibits specific performances in an accelerated weather resistance test with a sunshine weatherometer, and a structure having photocatalytic functions on a surface formed of the above photocatalyst film.