A single fuel cell, a plurality of which are to be stacked to form a fuel cell stack, includes a membrane electrode assembly having a structure including paired electrode layers and an electrolyte membrane held between the paired electrode layers, paired separators each forming a gas passage between the separator and the membrane electrode assembly, and a displacement absorber having a conductive property and interposed between one separator of the single fuel cell and an adjacent-side separator of another single fuel cell to be stacked adjacent to the single fuel cell. The displacement absorber is connected to at least any one of the separators.