NOVELTY - A gas barrier film (1) has a gas barrier layer (3) laminated on base material (2) and containing silicon oxycarbide and having composition changing along thickness direction. Carbon distribution curve exhibiting relationship with ratio of carbon atom number with respect to the total number of atoms of carbon, silicon and oxygen atoms has local maximum and local minimum, which are changing continuously, and has six or more local maximum. Inclination (a) of specific linear function derived from carbon atom ratio (y) and distance (x) from surface measured by least squares method is 0.03-0.7.    USE - Gas barrier film for organic electroluminescent element, solar cell, liquid crystal display element, electronic paper, thin-film transistor and touchscreen.    ADVANTAGE - The gas barrier film has excellent gas barrier performance and adhesiveness.    DETAILED DESCRIPTION - A gas barrier film has a gas barrier layer laminated on a base material and containing silicon oxycarbide and having composition changing along thickness direction. The carbon distribution curve exhibiting relationship with ratio of carbon atom number with respect to the total number of atoms of carbon, silicon and oxygen atoms has local maximum and local minimum, which are changing continuously with respect to the position change along thickness direction, and has six or more local maximum. Two arbitrary local maximum exists in region from gas barrier layer surface on opposite side to base material to depth of 1/3 with respect to thickness of gas barrier layer. Inclination (a) of linear function formula: y=ax+b derived from carbon atom ratio (y) in two arbitrary local maximum in region from 1/3-2/3, and two arbitrary local maximum in region from 2/3 to base material, and distance (x) from the surface measured by least squares method is 0.03-0.7. An INDEPENDENT CLAIM is included for manufacture of gas barrier film.    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional view of gas barrier film.    Gas barrier film (1)    Base material (2)    Gas barrier layer (3)