the cation exchange membrane 1 is disposed above the anion exchange membrane 2 for example a hydrogen gas must be introduced from the lower portion of the gas channel since the cation exchange membrane 1 is disposed on the upper side electroendosmotic water and product water flow downwards through the diffusion layer 3 by making use of these waters a reaction at the lower anion exchange membrane occurs since the hydrogen gas must be humidified by the reaction at the upper cation membrane 1 it recycles water in such a way that the moisture obtained in the lower anion membrane is fed upward the oxygen gas on the other hand recycles water obtained at the cation membrane 1 in the present invention the disposal of these membranes are therefore not limited to vertical one but can be determined as needed according to the gas feeding direction fig2 illustrates another embodiment of the present invention including the layout of a gas channel and exchange membrane fig2 a illustrates a disposal example wherein one gas channel crosses the anion exchange membrane 2 and cation exchange membrane 1 at plural points while fig2 b illustrates a disposal example wherein plural anion exchange membranes 2 and plural cation exchange membranes 1 are disposed alternately on the same plane and plural gas channels cross this plane the thickness of each of the cation exchange membrane and anion exchange membrane is not particular limited but can be determined freely it preferably falls within a range of about 10 u03bcm to 1 0 mm from the viewpoints of the efficiency of electrode reaction or stacking ease of cells fig3 schematically illustrates electrolysis of water when the fuel cell of.