The present invention is the natural gas (ethylene gas) occurred in the repertory that will be saved inside freezer, is crossed with outside air, and the freezer gas fittings for the freshness that can maintain freezer is provided. That is, the present invention is the ethyl alcohol natural gas outer drain internal by freezer (1), outside air, by the freezer cleaning coal gas device supplied automatically inside freezer (1). This is Kay(2) the internal heat exchanger (3) installed and heater (3a) and upper heat exchanger (3), air and heat exchange of the outside air in internal evacuated air, in order to manage (4) 5 to the 1st of offer outside air inside freezer (1), 2,2, inflow) and above-mentioned freezer (1), in order to drain the alcohol gas of internal generation, the 1st exhaust shop (7) installed in freezer (1) and an exhaust pipe (7) and second, 3 exhaust shops (9,11), in order to drain the fish pump (10) of second ethylene gas characterized by non-.
