Provided are an overheating detection unit and an oxygen concentrator capable of securing safety since, by attaching the overheating detection unit between the oxygen concentrator and a cannula, it is possible to reliably detect a high-temperature environment to cut the supply of oxygen when a user inhales oxygen using the cannula and is exposed to a fire or an abnormal high-temperature environment. An overheating detection unit (300) includes a main body (302) including a connecting member (330) connected to an oxygen outlet (15) and an oxygen outlet portion (310) connected to a tube (23) and also includes a housing (301) that covers the main body (302). The main body (302) includes a temperature sensor (453) disposed in the oxygen outlet portion (310) so as to detect the temperature of the oxygen outlet portion and a blocking structure portion (402) that blocks a passage between the connecting member (330) and the oxygen outlet portion (310) to thereby cut the supply of oxygen when the temperature sensor detects a temperature that is equal to or higher than a predetermined temperature.
