This surface-treated metal includes a metal, and a coated material on a surface of the metal, in which an outermost layer is a photocatalytic film that contains particles showing photocatalytic activity and an organic-inorganic composite resin, a volume ratio of the particles to the film is in a range from 0.5 to 50 vol %, the resin contains a siloxane bond and at least one group selected from the group consisting of an aryl group, a carboxyl group, an amino group, a hydroxyl group, and an alkyl group having 1 to 12 carbon atoms, the coated material has concaves on a surface thereof on the outermost layer side, an area of the outermost layer is 50% to 98% of an area of a surface of the metal, and a surface area of the outermost layer is 101% to 5000% of the area of the surface of the metal.