A method of depositing at least one functional film on at least one part of one or two faces of flat or curved substrates. The substrates are conveyed individually to a film-coating station and are advanced therein along the plane or neutral plane thereof. The film-coating station includes a film-applicator assembly including at least one axis perpendicular to the direction of advancement of the substrate and parallel to the advancement plane, at least one reel of film being mounted to the assembly. The method: conveys the leader of the film from each of the reels, which is to be applied to, and held against one face of, the substrate at a selected position, into the film-coating station; unwinds the reels such that the film can be applied in at least one strip to the advancing substrate; and cuts the film at a selected moment. Moreover, the new film leader is held to be ready to be applied at the selected position on the same substrate on a subsequent substrate.