In a fuel cell stack, a stack body includes a plurality of power generation cells stacked in a stacking direction, and a first dummy cell is provided at one end of the stack body in the stacking direction. The first dummy cell includes a dummy assembly, a dummy resin frame member, and a dummy joint separator. The dummy resin member includes a first resin sheet and a second resin sheet. An inner exposed portion is provided in an inner periphery of the first resin sheet. The inner exposed portion extends inward beyond an inner end of the second resin sheet. A first heat welding portion is provided discontinuously in a stack part where the inner exposed portion and the first electrically conductive porous sheet of the dummy assembly are stacked together. The dummy resin frame member and the dummy assembly are joined together by the first heat welding portion.