FUEL CELL

To provide a fuel cell configured to enable cell thickness reduction and low pressure loss. A fuel cell comprising a membrane electrode gas diffusion layer assembly, a frame member disposed around the membrane electrode gas diffusion layer assembly, and a pair of separators stacked on the frame member to sandwich the membrane electrode gas diffusion layer assembly and the frame member, wherein the separators include separator-side manifolds; wherein the frame member includes a skeleton connecting to the membrane electrode gas diffusion layer assembly, an opening for housing the membrane electrode gas diffusion layer assembly, frame member-side manifolds aligned and disposed to communicate with the separator-side manifolds, and a fluid introduction and derivation site between the opening and the frame member-side manifolds; wherein the fluid introduction and derivation site includes convexities to form a flow path for delivering a fluid in a horizontal direction of the frame member; and wherein a thickness of the convexities is larger than a thickness of the skeleton.