AIR PURGE DEVICE

Provided is a air purge device that can effectively discharge air. The air purge device includes: an air purge pipe (71) connected to a condenser (12) and configured to extract a mixed gas containing a refrigerant gas and air from the condenser (12); a separation film (23b) provided to the air purge pipe (71) and configured to separate, by a pressure difference, air from the mixed gas extracted by the air purge pipe (71); an exhaust pipe (81) configured to externally guide a gas containing air separated by the separation film (23b); a first valve (24) provided to the exhaust pipe (81); a vacuum pump (27) provided downstream of the first valve (24) in the exhaust pipe (81) and configured to externally discharge a gas present inside the exhaust pipe (81); and a control unit (50), and the control unit (50) activates the vacuum pump (27), opens the first valve (24), and then closes the first valve (24) to stop permeation of air caused by a pressure difference when detecting that a predetermined amount of air has permeated the separation film (23b).