TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The ratio of the thickness of organic layer to the thickness of inorganic layer is greater than or equal to 20, preferably greater than or equal to 30. The organic layer is obtained by curing a polymerizable composition containing a (meth)acrylate-base compound having a phosphate ester group. The (meth)acrylate-base compound having a phosphate ester moiety of formula (Ac1-O-X1-O-P(=O)(O-Z2)-O-Z1) (I). The organic layer has a: glass transition temperature of less than or equal to 100 degrees C, preferably less than or equal to 85 degrees C; and thickness of 5-10 mu m. The gas barrier film comprises at least two layers of the organic layer and at least two layers of the inorganic layer, alternately. The gas barrier film further comprises an: easy adhesive layer (2) formed on the substrate film; and organic layer directly on the surface of the inorganic layer, where the organic layer on the inorganic layer has the same composition as the composition of the organic layer laid under the inorganic layer. The inorganic layer has a thickness of 5-500 nm.Z1, Z2 = Ac2-O-X2-, H (both preferred), or a substituent having no polymerizable group;Ac1, Ac2 = acryloyl or methacryloyl; andX1, X2 = alkylene, alkyleneoxy, alkyleneoxycarbonyl and/or alkylenecarbonyloxy. EXAMPLE - Polyethylene naphthalate (PEN) film with an easy adhesive layer was cut into 20 x 20 cm2. Then on the surface of the easy adhesive layer of the PEN film, a polymerizable composition (composed of EBECRYL3702 (RTM: Polymerizable acrylate) (9 g), allyldiphenylphosphine oxide (1 g), UV polymerization initiator (0.6 g), and 2-butanone (190 g)) was coated using a wire bar coater. The thus-coated organic layer was irradiated with UV using a high-pressure mercury lamp in a chamber in which oxygen concentration was reduced to 0.1% by replacement with nitrogen, thus to form a cured organic layer of 0.55 mu m thick. Then an inorganic layer (aluminum oxide layer) of 50 nm thickness was formed on the surface of the organic layer, by a sputtering apparatus, using aluminum, argon, and oxygen as a target, discharge gas and reactive gas, respectively. In this way, the inorganic layer was stacked on the surface of the organic layer. Then another organic layer was formed on the surface of inorganic layer, and another inorganic layer was further formed on the organic layer, thus to obtain the gas barrier film.