Abstract: A high temperature fuel cell system includes upper and lower sheet gaskets including inner portions respectively covering an extending portion of the electrolyte membrane and outer portions combined with each other, wherein the extending portion of the electrolyte membrane is exposed from the electrodes, rubber gaskets that are disposed on the outer portions of the sheet gaskets seal a space between the conductive plates and the sheet gaskets, and an adhesive seals the outer portions of the lower sheet gasket and upper sheet gasket, and wherein ends of the inner portions of the upper and lower sheet gaskets are respectively disposed between edges of the electrodes and the electrolyte membrane.