An object of the present invention is to provide a method for producing a gas barrier film, capable of producing a gas barrier film which has production suitability in a roll-to-roll manner and is excellent in productivity and in gas barrier performance. The method for producing a gas barrier film including: a coating step for coating a first barrier layer formed on a base with a coating liquid containing a polysilazane compound to form a coating film; and an ultraviolet ray irradiation step for irradiation with a vacuum ultraviolet ray by light sources to form a second barrier layer, wherein an illuminance of the vacuum ultraviolet ray received on a coating film surface by the coating film from start to end of the irradiation with the vacuum ultraviolet ray is 160 mW/cm2 or less, there is a period T during which an illuminance of the vacuum ultraviolet ray on the coating film surface is 50 mW/cm2 or more and 160 mW/cm2 or less, and an amount of energy (E1) received on the coating film surface within T is 180 mJ/cm2 or more and 1800 mJ/cm2 or less.