Disclosed is a fuel cell stack which includes: a cell assembly formed of stacked unit cells, each composed of a membrane electrolyte assembly and separators which sandwich the membrane electrolyte assembly; a pair of collector plates A and B which sandwiches the cell assembly; a pair of end plates A and B which sandwiches the cell assembly and the collector plates; and an elastic member disposed between end plate A and collector plate A, wherein end plate A has a convexed portion and a concaved portion on a surface facing collector plate A, and the concaved portion of end plate A holds therein the elastic member, and a bottom surface of the concaved portion includes a second convexed portion and a second concaved portion.