To provide a system, a method and a device for supplying concentrated oxygen only by the quantity or for time optimum to a person inhaling concentrated oxygen.

This concentrated oxygen supply device is provided with an concentrated oxygen supply means 20 for releasing enriched oxygen; an organism measuring means 11 for measuring the health state of each subject; and a control means 10 actuating the organism measuring means 11 and controlling the enriched oxygen release action of the concentrated oxygen supply means 20 on the basis of the measured result. Physical reaction and change of each testee on the uptake of enriched oxygen are accurately recognized, and the optimum uptake quantity and supply time of concentrate oxygen to each subject are clarified with fixed standards so as to obtain the effect of supplying concentrated oxygen most effectively to each testee.