Power generating cell

A power generating cell comprising a membrane electrode assembly on which electrodes are provided on both sides of an electrolyte membrane, metal separators disposed on both sides of the membrane electrode assembly, and a resin frame member protruding outwardly from outer peripheral portions of the electrodes and surrounding the outer peripheral portions of the electrodes in a state of being sandwiched between the outer peripheral portion of one of the electrodes and the outer peripheral portion of another of the electrodes;

• wherein reaction gas flow fields are formed therein having a plurality of linear protrusions extending from one end to another end of the metal separators, and a plurality of linear flow field grooves formed between the plurality of linear protrusions, and which are configured to allow reaction gases to flow along power generating surfaces thereof from the one end to the other end;
• and
• in the power generating cell, seals are provided to surround the reaction gas flow fields and are configured to prevent leakage of the reaction gases;
• wherein on a surface on an opposite side from the electrolyte membrane on one of the electrodes, there are provided:
• an outer peripheral surface positioned on an outer peripheral portion of the one of the electrodes;
• a central surface located more inwardly than an inner end of the resin frame member;
• and
• a stepped portion connecting the outer peripheral surface and the central surface to each other;
• wherein a height of the central surface from the electrolyte membrane is lower than that of the outer peripheral surface;
• and
• among the plurality of linear protrusions, a protruding end surface of an end linear protrusion, which is positioned at an end of the reaction gas flow field in the flow field widthwise direction, is in contact with the central surface.