An electrochemical device for oxygen production which makes oxygen on both cathode and anode from air has been developed. The electrolytic cell consists of an air cathode, a catalytic decomposition mesh and a nickel anode. The electrolyser is composed of six single cells. The working surface area of a single cell is 0.02 m(2). Performance depends on factors such as the basic electrolyte concentration, temperature, air flow rate, gas flow distribution and current density. When the device is operated with 7 M KOH at room temperature and with an air flow rate of 0.4 m(3) h(-1) and current of 20 A, the oxygen evolution rate is 0.036 m(3) h(-1) and the oxygen purity is 99.5%. The current efficiency is 72.0%. The device has operated continuously for 12 months with stable performance.