Abstract: A fuel cell of the invention has unified a processing circuit processing a cell voltage output signal of a fuel cell stack and a connector connecting an circuit unit with terminals provided extending from separators of the fuel cell, thereby having abolished connection points (in which harnesses are attached and detached) of an electrical circuit unit with the connector. So, for connection, reliability can be improved, and downsizing is possible. Moreover, with a casing enclosing the connector and electrical circuit unit, the fuel cell can be made compact and the processing circuit can be surely protected thanks to being shielded from surroundings, thereby handling as a unit being able to be facilitated.

Abstract: The electrodeionization water producing apparatus comprising a depletion chamber packed with an ion exchange material, the depletion chamber being partitioned by a cation exchange membrane on one side and an anion exchange membrane on the other side, and concentrate chambers installed on both sides of the depletion chamber with the cation exchange membrane and the anion exchange membrane disposed inbetween, the depletion chamber and the concentrate chambers disposing between an anode chamber equipped with an anode and a cathode chamber equipped with a cathode, wherein the concentrate chambers are packed with an organic porous ion exchange material having a continuous pore structure in which the wall made from interconnected macropores contains mesopores with an average diameter of 1 to 1,000 &mgr;m. The apparatus ensures reduction of electric resistance and does not form scale in the concentrate chamber during long continuous operation.

Abstract: A bypass plate and an intermediate plate are interposed between a stack body and a negative electrode terminal of a fuel cell stack. An oxygen-containing gas passage extends through the bypass plate and the stack body. The intermediate plate has a small opening. The opening has a cross sectional area smaller than a cross sectional area of the oxygen-containing gas supply passage. The opening is formed by an extension extending into the oxygen-containing gas supply passage. The extension removes water in the oxygen-containing gas, and discharges the water into a bypass flow passage.