Disclosed is a polymer brush composite including a substrate, a solid layer disposed on the substrate and containing at least one of a metal or a metal oxide, and a plurality of polymer chains penetrating the solid layer in such a manner that one end of each of the polymer chains is disposed on the upper side of the substrate and the other end of each the polymer chains is exposed at a surface of the solid layer on an opposite side of the solid layer to the substrate. The polymer brush composite exhibits good adhesion between an organic polymer compound and an inorganic material and has the surface the organic polymer compound and the inorganic material uniformly coexist.