FUEL CELL STACK AND OPERATION METHOD FOR FUEL CELL STACK

According to the present embodiment, a fuel cell stack comprises a cell stack having a plurality of unit cells stacked therein, each of the unit cells including an electrolyte membrane, a fuel-electrode porous passage plate, and an oxidant-electrode porous passage plate, wherein in the cell stack, at least a part of one main surface of a conductive fuel-electrode porous passage plate is in contact with one main surface of a conductive oxidant-electrode porous passage plate, and a capillary force of water contained in a hydrophilic micropores of the conductive fuel-electrode porous passage plate and the conductive oxidant-electrode porous passage plate prevents an oxidant gas in an oxidant-electrode passage and a fuel gas in a fuel-electrode passage from directly mixing together.