Abstract: A method of preparing cryogenic air for use in cryotherapy procedures, using liquid nitrogen and gaseous oxygen, characterized in that liquid nitrogen (1) is fed from a cryogenic nitrogen tank (2) via a cryogenic duct (3) to a reactor (4), wherein simultaneously a gas (7) containing oxygen in a concentration from 20% to 100% is fed from an oxygen source (5) to the reactor (4), through a gas duct (6), then, in the reactor (4), the liquid nitrogen (1) is evaporated using the gas (7) and both these components are mixed together, forming a cold breathable mixture (8), cooled to a set temperature of minus 80° C. to minus 160° C., which is further fed through a cold duct (9) terminated with an outlet (10) to a cryochamber (11).