Abstract: The disclosure relates to an electrochemical treatment of liquids and production of gases. Increased operating efficiency of an electrochemical device is achieved through the combination of measures: (1) sealing of the device on an element-by-element basis; (2) transfer of the liquid and gaseous phase interface into a passive extension of an anode chamber; (3) utilization of a tubular cathode as an inner wall and a cylindrical anode with an external coating as an outer wall; (4) positioning of channels and determining their dimensions so as to maintain helicity of electrolyte movement combined with the increase of the production output; (5) positioning and design of terminals, which provide for the reduction of their heating; and (6) ability of the device to operate under the conditions, when its longitudinal axis deviates from the vertical line by an angle of ??85° and under pumping conditions.