NOVELTY - Cured organopolysiloxane resin film having gas barrier properties comprises a fiber-reinforced film made of a cured organopolysiloxane resin which is transparent in the visible region.    USE - The cured organopolysiloxane resin film is useful as a film substrate for transparent electrodes in electroluminescent displays, or liquid-crystal displays; as a back sheet for crystalline silicon solar cells; and as a substrate for amorphous silicon solar cells.    ADVANTAGE - The cured organopolysiloxane resin film exhibits excellent gas barrier properties.    DETAILED DESCRIPTION - Cured organopolysiloxane resin film having gas barrier properties comprises a fiber-reinforced film made of a cured organopolysiloxane resin which is transparent in the visible region and obtained by a cross-linking reaction between (A) an organopolysiloxane resin that is represented by the average siloxane unit formula RaSiO(4-a)/2 where R is 1-10C monovalent hydrocarbyl and a is a number with an average value in the range of 0.5 not less than a not less than 2 and that has an average of at least 1.2 2-10C unsaturated aliphatic hydrocarbyls per molecule and (B) an organosilicon compound having at least two silicon-bonded hydrogen atoms per molecule in the presence of (C) a hydrosilylation reaction catalyst, and a transparent inorganic layer selected from a silicon oxynitride layer, silicon nitride layer, and silicon oxide layer that is formed on the fiber-reinforced film, where a cured organopolysiloxane layer selected from: (a) an organic functional group-containing cured organopolysiloxane layer; (b) a silanol group-containing cured organopolysiloxane layer free from the organic functional group; (c) a hydrosilyl group-containing cured organopolysiloxane layer free from the organic functional group; (d) a layer of cured organopolysiloxane having organic groups produced by polymerization between polymerizable organic functional groups of an organopolysiloxane having two or more polymerizable organic functional groups in one molecule; and (e) a cured organopolysiloxane layer formed by polymerizing the polymerizable organic functional groups with each other and reacting the cross-linking groups with each other of a polymerizable organic functional group- and cross-linking group-containing curable organopolysiloxane is interposed between the fiber-reinforced film and the transparent inorganic layer; or cured organopolysiloxane resin film having gas barrier properties comprises a fiber-reinforced film made of a cured organopolysiloxane resin which is transparent in the visible region and obtained by a cross-linking reaction between (A) an organopolysiloxane resin that is represented by the average siloxane unit formula RaSiO(4-a)/2 where R is 1-10C monovalent hydrocarbyl and a is a number with an average value in the range of 0.5 not less than a not less than 2 and that has an average of at least 1.2 2-10C unsaturated aliphatic hydrocarbyls per molecule and (B) an organosilicon compound having at least two silicon-bonded hydrogen atoms per molecule in the presence of (C) a hydrosilylation reaction catalyst, and a silicon oxynitride layer that is formed on the fiber-reinforced film, where a molar ratio of hydrosilyl groups of component (B) to unsaturated aliphatic hydrocarbyls of component (A) is within the range of 1.05 to 1.50, and the cured organopolysiloxane resin has hydrosilyl groups. An INDEPENDENT CLAIM is a method of producing the cured organopolysiloxane resin film having gas barrier properties comprising: (I) forming a cured organopolysiloxane layer selected from (a)-(e) above, by coating, on a fiber-reinforced film made of a cured organopolysiloxane resin which is transparent in the visible region and obtained by a cross-linking reaction between (A) an organopolysiloxane resin that is represented by the average siloxane unit formula RaSiO(4-a)/2 where R is 1-10C monovalent hydrocarbyl and a is a number with an average value in the range of 0.5 not less than a not less than 2 and that has an average of at least 1.2 2-10C unsaturated aliphatic hydrocarbyls per molecule and (B) an organosilicon compound having at least two silicon-bonded hydrogen atoms per molecule in the presence of (C) a hydrosilylation reaction catalyst; and then (II) forming a transparent inorganic layer selected from a silicon oxynitride layer, silicon nitride layer, and silicon oxide layer, by vapor deposition, on the cured organopolysiloxane layer; or a method of producing the cured organopolysiloxane resin film having gas barrier properties comprising forming a silicon oxynitride layer, by reactive ion plating, on a fiber-reinforced film made of a hydrosilyl group-containing cured organopolysiloxane resin which is transparent in the visible region and obtained by a cross-linking reaction between (A) an organopolysiloxane resin that is represented by the average siloxane unit formula RaSiO(4-a)/2 where R is 1-10C monovalent hydrocarbyl and a is a number with an average value in the range of 0.5 not less than a not less than 2 and that has an average of at least 1.2 2-10C unsaturated aliphatic hydrocarbyls per molecule and (B) an organosilicon compound having at least two silicon-bonded hydrogen atoms per molecule in an amount sufficient to provide a molar ratio of hydrosilyl groups of component (B) to unsaturated aliphatic hydrocarbyls of component (A) within the range of 1.05 to 1.50 in the presence of (C) a hydrosilylation reaction catalyst; or a method of producing the cured organopolysiloxane resin film having gas barrier properties comprising: (I) forming a cured organopolysiloxane layer selected from (a)-(e) above; (II) forming a transparent inorganic layer selected from a silicon oxynitride layer, silicon nitride layer, and silicon oxide layer, by vapor deposition, on the cured organopolysiloxane layer or silicon oxynitride layer; (III) forming a cured polymer layer, by coating, on the transparent inorganic layer; and then (IV) forming a transparent inorganic layer selected from a silicon oxynitride layer, silicon nitride layer, and silicon oxide layer, by vapor deposition, on the cured polymer layer, or by reactive ion plating, on the cured polymer layer.