Patent ID: 8597851

Claim:
A polymer electrolyte fuel cell comprising: a membrane-electrode assembly including a polymer electrolyte membrane and a pair of electrodes sandwiching a portion of the polymer electrolyte membrane, the portion being located on an inner side of a peripheral portion of the polymer electrolyte membrane; an electrically-conductive first separator having a plate shape, disposed to contact one of the pair of electrodes of the membrane-electrode assembly, and including a first reactant gas channel formed on one main surface of the first separator and having a bent portion, said one main surface contacting said one of the pair of electrodes; and an electrically-conductive second separator having a plate shape, disposed to contact the other one of the pair of electrodes of the membrane-electrode assembly, and having a second reactant gas channel formed on one main surface of the second separator and having a bent portion, said one main surface contacting said other one of the pair of electrodes, wherein: the first reactant gas channel includes a first overlapping portion, a first portion and a first particular portion within a region of said one of the pair of electrodes, when viewed in a thickness direction of the first separator, the first overlapping portion is a portion where the first reactant gas channel extending from an upstream end thereof first overlaps the second reactant gas channel, the first portion is located downstream of the first overlapping portion and is a portion where the first reactant gas channel first separates from the second reactant gas channel, the first particular portion includes the first portion, a width of the first reactant gas channel in the first particular portion is smaller than a width of the first reactant gas channel in a upstream portion located upstream of the first particular portion of the first reactant gas channel and a width of the first reactant gas channel in a downstream portion located downstream of the first particular portion of the first reactant gas channel.