NOVELTY - A gas-barrier film comprises resin base material and gas barrier layer containing silicon (Si) atom, oxygen atom, and carbon (C) atom formed on greater than or equal to 1 surface side of resin base material. Change rate of Si-C bond before and after a 300-hour preservation of gas barrier layer is less than or equal to 15% at 85 degrees C and 85% relative humidity (RH) environment. A composition changes to a layer thickness direction continuously.    USE - A gas-barrier film for electronic devices, such as organic electroluminescent element, LCD element, thin-film transistor, touchscreen, electronic paper, photovoltaic (PV) solar cell.    ADVANTAGE - The gas-barrier film has stable long-term gas barrier performance at high-temperature, high-humidity environment, and excellent adhesiveness.    DETAILED DESCRIPTION - A gas-barrier film comprises resin base material and gas barrier layer containing silicon (Si) atom, oxygen atom, and carbon (C) atom formed on greater than or equal to 1 surface side of resin base material. Change rate of Si-C bond before and after a 300-hour preservation of gas barrier layer is less than or equal to 15% at 85 degrees C and 85% relative humidity (RH) environment. A composition changes to a layer thickness direction continuously. Absolute value of difference of extreme value with largest C atom ratio (local maximum), which has greater than or equal to 1 extreme value, and minimum extreme value (local minimum) is greater than or equal to 5 at.%, according to distance from surface of gas barrier layer in layer thickness direction of gas barrier layer among distribution curves of each constituent element based on element distribution measurement of depth direction by X ray photoelectron spectroscopy of gas barrier layer, and carbon distribution curve which shows relationship of ratio of C atom (at.%) with respect to total amount (100 at.%) of Si atom, oxygen atom, and C atom. In greater than or equal to 90% of region of the whole layer thickness of gas barrier layer, average atomic ratio of each atom with respect to total amount (100 at.%) of Si atom, oxygen atom, and C atom has magnitude correlation of the order represented by equation: C average atomic ratio less than or equal to Si average atomic ratio less than or equal to oxygen average atomic ratio (A), or equation: C average atomic ratio greater than or equal to Si average atomic ratio greater than or equal to oxygen average atomic ratio (B).