Gas barrier film

A method for manufacturing a rolled gas barrier film comprising an inorganic compound thin film formed on at least one surface of a plastic film, which comprises;

• a step of forming the inorganic compound thin film by heating and vaporizing aluminum oxide particles having a particle size of 2 to 6 mm and magnesium oxide particles having a particle size of 2 to 6 mm to make vapors separately, mixing the vapors in vapor phase, and then depositing the vapors on at least one surface of the plastic film;
• and
• a step of winding the plastic film on which the inorganic compound thin film is formed to make the rolled gas barrier film;
• wherein
• the inorganic compound thin film contains aluminum oxide, magnesium oxide, and optionally other compounds,
• the ratio of magnesium oxide is not less than 5 mass % and not more than 90 mass % of the total mass of aluminum oxide and magnesium oxide contained in the inorganic compound thin film,
• the thickness of the inorganic compound thin film is 5 to 80 nm,
• the gas barrier film has a rate of change of water vapor transmission rate (ΔWVTR) of not more than 50% after being treated at 40° C. and 90% RH for 50 hours.