Fuel cell stack

A fuel cell stack comprising a plurality of single cells stacked, and a manifold that is provided so as to extend through the plurality of single cells and allows a fluid to flow therein, wherein:

• each single cell of the plurality of single cells includes:
• a first separator including a protrusion including (i) a seal portion that surrounds a periphery of the manifold and (ii) a fluid passage portion,
• a first member disposed on a side of the first separator such that (i) a first space is arranged between the protrusion and the first member and (ii) the fluid passage portion allows the fluid to flow between the manifold and a second space on an opposite side of the seal portion from the manifold via the first space, the side being opposite to a side on which the seal portion projects, and
• a second member that is provided on an opposite side of the first member from the first separator and includes a first elastic member;
• the seal portion of a first single cell from among the plurality of single cells is in abutment with the second member of a second single cell adjacent to the first single cell;
• the first member of the first single cell includes a flat-and-bulge portion in a surface of the first member, the surface facing the seal portion, the flat-and-bulge portion extending along a region where the seal portion and the second member of the second single cell abut against each other;
• wherein the region extends in a flat-and-bulge portion direction which is perpendicular to a direction of the fluid flow between the manifold and the second space.