NOVELTY - A dope containing solid electrolyte and an organic solvent is made to flow-spread on a support (111) to form a spread film (24a). The air surface side of spread film is dried, and a skin layer having different surface tension from support side is formed. Spread film is peeled off from support, and used as moisture film containing solvent. Moisture film is dried and used as solid electrolyte film. A liquid (65a, 66a), which is a poor solvent of electrolyte and having low boiling point than solvent is contacted with spread film and/or moisture film before drying.    USE - For manufacturing solid electrolyte film used for electrode membrane composite of fuel cell (both claimed) used as power supply for robots, portable generator, field lighting equipment, flashlight, motor vehicles, household appliances and portable devices, such as mobile telephone, mobile notebook personal computer, electronic still camera, personal digital assistance, video camera, handheld game machine, mobile server, wearable personal computer and mobile display.    ADVANTAGE - The solid electrolyte film having high ionic conductivity, excellent mechanical strength and quality is continuously, economically and quickly manufactured. The rate of drying is improved due to pressure reduction at the time of drying. The electrolyte film provides electrode membrane joint component having excellent electromotive force.    DETAILED DESCRIPTION - A dope containing solid electrolyte and an organic solvent is made to flow-spread on a support from a spread die to form a spread film. The air surface side of spread film is dried for less than 60 seconds, and a skin layer having different surface tension from support side is formed immediately after spreading dope. Spread film is peeled off from the support, and used as moisture film containing organic solvent. The moisture film is dried and used as solid electrolyte film. A liquid which is a poor solvent of solid electrolyte and has lower boiling point than that of the organic solvent is contacted with spread film and/or moisture film before drying spread film and/or moisture film.    INDEPENDENT CLAIMS are included for the following:    (a) manufacturing equipment of solid electrolyte film, which has a spread apparatus for flow-spreading dope, primary drying apparatus for drying air surface side, a peeling apparatus for peeling spread film, secondary drying apparatus for drying moisture film, and a liquid contactor for contacting liquid, and spread film and/or moisture film;    (b) solid electrolyte film;    (c) electrode membrane composite, which has the solid electrolyte film, an anode contacted with one surface of solid electrolyte film, and a cathode. The anode produces proton from hydrogen-containing substance. The cathode produces water from proton passed through solid electrolyte film, and a gas; and    (d) fuel cell, which has electrode membrane composite, and a collector contacting the composite. The collector delivers electron of anode and cathode.    DESCRIPTION OF DRAWING(S) - The figure shows the schematic view of solid electrolyte film manufacturing equipment. (Drawing includes non-English language text).    Dope manufacturing equipment (10)    Spread film (24a)    Liquids (65a,66a)    Drying chamber (69)    Support (111)