The object of this invention is to provide a winding type plasma CVD apparatus in which quality of a layer can be made uniform by supplying a reaction gas uniformly to a deposition area of a film, and can perform a self-cleaning process of a deposition portion in the path of deposition onto the film.A film (22) is supported between a pair of movable rollers (33, 34) arranged on the upstream side and downstream side of the deposition portion (25) with regard to the traveling direction of the film, and then the film (22) is made to travel substantially linearly at the deposition position. Consequently, the distance between a shower plate (37) and the film (22) is kept constant, and the quality of the layer is made homogeneous. The film is heated by means of a metal belt (40) traveling simultaneously on the back side of the film. The moveable rollers (33, 34) ascend from the deposition position to the self-cleaning position, and the film (22) can be separated from the shower plate (37). Self-cleaning can be carried out in the path of the deposition onto the film by closing the aperture of a mask (51) with a shutter (65), thereby preventing leakage of cleaning gas.