NOVELTY - An organic-thin-film forming apparatus consists of an airtight reaction chamber (31). A unit (33) is provided for introducing gaseous fluid containing organic molecules, or solution to the reaction chamber. A substrate stage (311) is provided for holding the substrate (30). A unit (322) for removing by-product produced when forming a chemical bond, is connected with the reaction chamber. Unimolecular layer(s) containing the organic molecules, which becomes the substrate face, is laminated through a chemical bond, to form an organic thin film.    USE - Apparatus is used for forming organic thin films (claimed) of semiconductor devices e.g. thin-film transistors, light-emitting devices, and solar cells. Uses include but are not limited to insulating layers, interlayer insulation films, passivation films, semiconductor layers, organic electroluminescent carrier transport layers, light-emitting layers, n-layers, p-layers, i-layers, and electrode films.    ADVANTAGE - The apparatus enables efficient and quick formation of high-quality organic thin films, with high yield. The formed thin film has excellent heat stability and durability. Corrosion of organic thin film by hydrochloric acid is suppressed. The by-products of organic matter produced by reaction are removed efficiently.    DETAILED DESCRIPTION - An organic-thin-film forming apparatus consists of an airtight reaction chamber. A unit is provided for introducing gaseous fluid containing organic molecules, or solution to the reaction chamber. A substrate stage is provided for holding the substrate to be formed into a film. A discharge unit (34) discharges the fluid from the reaction chamber. A unit for removing by-product produced when forming a chemical bond, is connected with the reaction chamber. Unimolecular layer(s) containing the organic molecules, which becomes the substrate face, is laminated through a chemical bond, to form an organic thin film. An INDEPENDENT CLAIM is included for formation method of organic thin film.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the organic-thin-film forming apparatus.    Substrate (30)    Reaction chamber (31)    Gaseous-fluid introduction unit (33)    Fluid discharge unit (34)    Substrate stage (311)    By-product removal unit (322)