PURPOSE: To enable oxygen to be generated continuously with an oxygen generating apparatus by allowing oxygen in the air to be absorbed in a cooled liq. medium for carrying oxygen, heating the medium to release the oxygen, and recycling the oxygen-free medium.

CONSTITUTION: An oxygen carrying liq. medium such as perfluorotributylamine cooled with cooler 6 in cooling vessel 1 filled with antifreezing fluid 2 such as brine is introduced into the 1st spraying chamber 8 through piping 7, sprayed from nozzles 9, and contacts to air fed from gas introducing hole 10 to dissolve oxygen. The oxygen-dissolved cold medium is takne out of taking-out pipe 13, heated with heater 14, and sprayed from nozzles 16 in the 2nd spraying chamber 15 to release the dissolved oxygen. The released oxygen is then freed of droplets of the liq. medium in a vapor-liq. separator 19, and oxygen is taken out of oxygen taking-out hole 20.