The invention provides a fuel cell comprising one or more cells (102) stacked therein, each of the cells (102) including: an MEA (4) having a polymer electrolyte membrane (7) and a pair of gas diffusion layers (5) sandwiching the polymer electrolyte membrane (7) except a peripheral region of the polymer electrolyte membrane (7); and a pair of self-sealing separators (1) disposed so as to sandwich the MEA (4), each of the self-sealing separators (1) being formed in a plate-like shape as a whole and composed of a separating part (41) having electrical conductivity and a sealing part (40) having more elasticity than the separating part (41), at least the separating part (41) being in contact with an associated one of the gas diffusion layers (5), the sealing part (40) being in contact with the peripheral region of the polymer electrolyte membrane (7) so as to enclose the associated one of the gas diffusion layers (5), wherein each self-sealing separator (1) has a lower area (11) for accommodating a raised portion (51) formed on the periphery of the outer surface of the associated gas diffusion layer (5) and the sealing part (40) is disposed within the lower area (11).