NOVELTY - A gas barrier film comprises a resin base material and a gas barrier layer formed on one or more surface side of the resin base material. The gas barrier layer (L1) comprises carbon atom, silicon atom, oxygen atom, and nitrogen atom, and in a carbon distribution curve which represents the relationship between the distance from surface in thickness direction of the layer, and the ratio of quantity of carbon atoms to total content of all atoms, there is at least one extreme value, and the absolute value of difference between maximum value and minimum value is 5 atomic% or more.    USE - Gas barrier film. Uses include but are not limited to solar cell element, organic electroluminescent element, liquid-crystal-display element and packaging material for foodstuff, industrial products and pharmaceutical products.    ADVANTAGE - The gas barrier film has excellent gas barrier property and bending resistance, and reduced curl.    DETAILED DESCRIPTION - A gas barrier film comprises a resin base material and a gas barrier layer formed on one or more surface side of the resin base material. The gas barrier layer (L1) comprises carbon atom, silicon atom, oxygen atom, and nitrogen atom, and in a carbon distribution curve which represents the relationship between the distance from surface in thickness direction of the layer, and the ratio of quantity of carbon atoms to total content of all atoms, there is at least one extreme value, and the absolute value of difference between maximum value and minimum value is 5 atomic% or more, and in nitrogen distribution curve representing the relationship between distance from surface and ratio of quantity of nitrogen to total content of all atoms, the maximum value is 0.5-10 atomic%, and in regions with 90% or more of the entire layer thickness, the average atomic ratio of each of atoms with respect to total content of all atoms satisfies the relations: carbon atomic ratio more than silicon atomic ratio more than oxygen atomic ratio more than nitrogen atomic ratio (I), and oxygen atomic ratio more than silicon atomic ratio more than carbon atomic ratio more than nitrogen atomic ratio (II). An INDEPENDENT CLAIM is included for manufacture of gas-barrier film, which involves forming gas barrier layer (L1) on surface side of the resin base material.