To enable application difficult heretofore of a fluoroplastic resin coating film to every base material such as a metal material, a plastic material, a stone material and the like at the normal temperature or a low temperature in a high adhesion state.

In this adhesion treatment method of a fluoroplastic film, a known functional coating agent (comodity name: Akuamica) "a silica coating agent comprising perhydropolysilazane (the grade of Akuamica is NL (palladium catalyst), NP, SP, UP, an aerosol can (amine catalyst) of a normal temperature curing type)" is applied as a primer and the fluoroplastic resin coating film (e.g; commodity name: FG 5010 or the like) is laminated on the surface of the primer layer.