A fuel cell separator has a sandwiching section. The sandwiching section is connected to a fuel gas manifold through a bridge, and connected to an oxygen-containing gas manifold through a bridge. The circumferential length R of the sandwiching section, the width H of the bridges the length L of the bridges, and the outer diameter D of the manifolds satisfies relationships of 0.03≦H/R≦0.20, 0.01≦L/R≦0.55, and 0.06≦D/R≦0.32.