A fuel cell sealing structure has a power generating body, and first and second separators arranged in both sides in a thickness direction of the power generating body. On a surface in one side in a thickness direction of the first separator, formed integrally first and second sealing protrusions respectively brought into close contact with an outer peripheral portion of the power generating body and the second separator in an outer peripheral side of the first sealing protrusion, and a short circuit prevention rib protruding in line with the first and second sealing protrusions by an electrically insulating rubber-like elastic material. On a surface in another side thereof, formed integrally a third sealing protrusion brought into close contact with a surface in an opposite side to the power generating body in the second separator, by the electrically insulating rubber-like elastic material.