PURPOSE: To make the diffusion of reaction gas and the supply of an electrolyte so easy and a long stable cell characteristic maintainable by dipping an electrode in an electrolytic solution regulated into the specified concentration, and reserving this electrolytic solution in a porous part of the electrode.

CONSTITUTION: A ribbed electrode 2 is dipped in a phosphoric acid solution, and phosphoric acid is kept in its pore. Next, the electrode 2, a matrix layer 1 being impregnated with the phosphoric acid in advance and an electrode 3 turning to the oxidizer electrode side are all integrated on one, thereby forming a cell. When this cell is made to rise in temperature and generated for power before starting, the phosphoric acid impregnated in the electrode 2 is enriches and its volume is reduced. Consequently, the phosphoric acid so far filled up in the pore of the electrode 2 merely comes fill up a part, whereby reaction gas is diffused around via the pore, preventing a blocking phenomenon from occurring. And, concentration of the phosphoric acid is altered whereby a passage of the pore is optimally adjustable. Thus, an electrolytic solution is reserved in the whole electrode so that a higher cell characteristic is maintainable over a long period of time.