An objective of this invention is to provide a separator for a fuel cell whereby a fuel, air or cooling water can be evenly and efficiently fed. In a separator for a fuel cell comprising fuel channels 105 in one side and cooling water channels 106 in the other side, the regions where the fuel channels 105 and the cooling water channels 106 are formed rectangular. The fuel gas is fed from a first fuel-feeding manifold 107 and discharged from a first fuel-discharging manifold 109 to the outside of the cell. The cooling water is fed from a first cooling-water-feeding manifold 111 and discharged from a first cooling-water-discharging manifold 113 to the outside of the cell.