NOVELTY - An electrolyzer comprises electrolytic vessel (10) filled with electrolyte solution, positive electrode (12) and negative electrode (13) which are immersed in electrolyte solution in electrolytic vessel, bipolar electrodes (14) which are positioned between both electrodes, mutually insulate both electrodes and voltage-divide voltage between both electrodes, power supply device which applies direct current alternating voltage to both electrodes, and sealing lid (18) which seals electrolytic vessel.    USE - An electrolyzer.    ADVANTAGE - The electrolyzer can generate gas emitted by electrolysis in large quantities efficiently, separate liquid from gas effectively, and perform continuous operation by little maintenance over a long time.    DETAILED DESCRIPTION - An electrolyzer comprises electrolytic vessel (10) filled with electrolyte solution, positive electrode (12) and negative electrode (13) which are immersed in electrolyte solution in electrolytic vessel, bipolar electrodes (14) which are positioned between both electrodes, mutually insulate both electrodes and voltage-divide voltage between both electrodes, power supply device which applies direct current alternating voltage to both electrodes, sealing lid (18) which seals electrolytic vessel, discharge port which discharges mixed gas of hydrogen and oxygen generated by electrolysis, gas-liquid separation apparatus which separates mixed gas emitted in foamy state with electrolytic vessel, first gas-liquid separation apparatus which separates liquid part from mixed gas, bottomed separation chamber divided into rooms by partition, opening provided in partition and bottom of chamber, first separation chamber through which mixed gas flows towards upper part from lower part, and baffle plates which have clearance gap through which mixed gas flows between one part and inner wall of first separation chamber.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of deposit removal apparatus.    Electrolytic vessel (10)    Positive electrode (12)    Negative electrode (13)    Bipolar electrodes (14)    Sealing lid (18)