To provide an oxygen concentrator capable of ensuring safety by cutting off oxygen in a case exposed to a fire or abnormal high temperature environment when a user inhales oxygen using a cannula.

The oxygen concentrator includes a compressor 10 for compressing raw material air to produce compressed air, an oxygen outlet part 100 for issuing oxygen obtained from the compressed air, the coupler 17 attached to the tube 72 of the cannula 70 to connect the tube 72 to the oxygen outlet part 100 in a detachable manner and having a temperature sensor 400 and a control part 200 for stopping the operation of the compressor 10 when the temperature detected by the temperature sensor 400 reaches predetermined temperature or above to cut off the supply of oxygen.