NOVELTY - A gas barrier film has gas barrier layer containing carbon atoms, silicon atoms and oxygen atoms, on a resin substrate. In the carbon distribution curve, obtained by depthwise element analysis of the gas barrier layer and which represents relationship between carbon/silicon atomic ratio, and depth from the surface of gas barrier layer, has at least one local maximum. The carbon distribution curve has at least one peak such that there is a difference of 5 atomic% or more between carbon atomic ratio at local maximum and minimum observed in depthwise region.    USE - Gas barrier film is used to seal electronic devices (claimed) e.g. thin-film transistors, touchscreens, electronic papers, solar cell elements, organic electroluminescence elements and LCD elements. Can also be used for packaging foodstuffs, industrial products and pharmaceuticals.    ADVANTAGE - The gas barrier film has excellent durability, gas barrier performance, and stability in high-temperature and high-humidity environment.    DETAILED DESCRIPTION - A gas barrier film has gas barrier layer containing carbon atoms, silicon atoms and oxygen atoms, on a resin substrate. In the carbon distribution curve, obtained by depthwise element analysis of the gas barrier layer by X-ray photoelectron spectroscopy and which represents relationship between carbon/silicon atomic ratio, and depth from the surface of the gas barrier layer, has at least one local maximum. The carbon distribution curve has at least one peak such that there is a difference of 5 atomic% or more between the carbon atomic ratio at the local maximum and the minimum carbon atomic ratio observed in depthwise region of 20 nm centered on the depth at which the local maximum appears, and when the gas barrier layer is subjected to nano-scratching in a depthwise region of 10 nm centered on the depth at which the peak appears, the obtained depthwise friction distribution has an average maximum value/minimum value ratio of 1.13 or less. An INDEPENDENT CLAIM is included for manufacture of gas barrier film, which involves forming gas barrier layer by vapor deposition on the resin base material, directly coating a coating liquid containing silicon compound, irradiating UV-light, and forming a silicon-containing layer on the gas barrier layer. The resin base material, vapor deposition gas barrier layer, and silicon-containing layer are heated at 50 degrees C or more.