Patent ID: 8304126

Claim:
A fuel cell which is supplied with two reactant gases flowing separately from each other and generates electric power therefrom, the fuel cell comprising: a stack-structured member comprising a plurality of solid electrolyte fuel cell units stacked on one another in a stacking direction, wherein inter-unit spaces are provided between the respective fuel cell units and one of the two reactant gases is supplied to the respective inter-unit spaces and configured for use in power generation; and a casing for housing the stack-structured member including a peripheral wall surrounding the stack-structured member, the peripheral wall provided with a gas inlet opening configured to introduce the one of the two reactant gases into the inter-unit spaces and a gas outlet opening configured to discharge the one of the two reactant gases, wherein a total opening width dimension of the gas inlet opening is greater than a total opening width dimension of the gas outlet opening, wherein, in a cross section perpendicular to the stacking direction, an outer peripheral edge portion of each of the fuel cell units comprises: a first segment of a first length extending along the gas outlet opening; a second segment of a second length extending along the gas inlet opening, the second length being greater than the first length; and a third segment and a fourth segment disposed between the first and second segments, the third and fourth segments connecting the first and second segments and extending along the peripheral wall.