PURPOSE: To enhance the durability of a film and facilitate extension of the film in a method of fixing the film used for horticultural houses by charging a cushioning material to at least one or more portions of film fixing members, with which the film is brought into contact.

CONSTITUTION: A cushioning material 4 is charged (applied) to at least one or more portions of film fixing members for the film used for plant-horticultural houses, for example, a Vinypet (registered) 2 of U-shaped cross-section and a wire spring 3, with which the film is brought into contact. Raw material for the film is not limited by quality, but a highly durable raw material can be used. Especially, fluorine-containing resin is preferably used, and as the fluorine-containing resin, ethylene-tetrafluoroethylene copolymer (ETFE) is suitably used. As the cushioning material, plastics is suitably used in general.