Patent ID: 7993790

Claim:
A fuel cell comprising: fuel cell units each having disposed in a stacking direction a fuel supply space disposed on one side of a polymer electrolyte layer and isolated from the atmosphere, and an oxidizer supply space disposed on another side of the polymer electrolyte layer and communicating with the atmosphere; a spacing holding member for supporting a thickness of the oxidizer supply space at a position outside a power generation region of the polymer electrolyte layer; and at least one pair of through-holes, which penetrate the fuel cell from one end to another end in the stacking direction, which are isolated from the atmosphere, and which communicate with the fuel supply space, disposed at planar positions having the power generation region located therebetween, wherein a fastening member is disposed in at least one through-hole of the pair of through-holes and has a thread ridge, and wherein a groove structure is provided in the thread ridge continuously in an axial direction of the fastening member.