NOVELTY - The fuel cell (FC) has a membrane electrode assembly (M) that is comprised of a structure including paired electrode layers (2,3) and an electrolyte membrane (1) held between the paired electrode layers. Paired separators (5A,5B) are provided to form a gas passage (4A,4B) between the separator and the membrane electrode assembly. A displacement absorber (6) is located between one separator of single fuel cell and adjacent-side separator of another single fuel cell to be stacked adjacent to the single fuel cell. The displacement absorber is connected to the separators.    USE - Single fuel cell such as polymer electrolyte fuel cell of fuel cell stack (claimed) for power source mounted in vehicle.    ADVANTAGE - The electrical contact resistance between the adjacent single fuel cells can be reliably reduced. The displacement absorber is connected to the one separator, and tight contact between two portions reduces the electrical contact resistance. Since the separator and displacement absorber are connected to each other by welding, the connection state is tighter and contact resistance can be reduced. The single fuel cell can achieve drastic reduction in electrical contact resistance between the separators and the displacement absorber. Single fuel cell can reduce the contact resistance of the entire fuel cell, and power generation performance can be improved. The performance of the displacement absorber is impaired, and connection can be easily and surely achieved. Since end portion of displacement absorber is located in the cooling fluid passage is held between and connected to the separators, the reliability and durability of the displacement absorber can be improved. Deterioration in corrosion resistance of the separator made of stainless steel due to thermal hysteresis in welding can be prevented.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) fuel cell stack; and    (2) method for manufacturing fuel cell stack.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the single fuel cell of fuel cell stack.    Electrolyte membrane (1)    Paired electrode layers (2,3)    Gas passages (4A,4B)    Paired separators (5A,5B)    Displacement absorber (6)    Single fuel cell (FC)    Membrane electrode assembly (M)