A surface modification method for modifying the surface of an oxide wherein the surface modification method is provided with a step for preparing a surface modification composition that mixes a modification agent having a perfluoropolyether chain, a first modification promoter containing an inorganic acid, and a second modification promoter containing a metal, metal salt, or organic metal, and a coating step for applying the surface modification composition to the surface of an oxide layer. A surface modification composition simultaneously containing a modification agent having a perfluoropolyether chain, a first modification promoter containing an inorganic acid, and a second modification promoter containing a metal, metal salt, or organic metal. A surface modification composition set provided with a modification agent having a perfluoropolyether chain, a first modification promoter containing an inorganic acid, and a second modification promoter containing a metal, metal salt, or organic metal. An antifouli
