NOVELTY - Fuel cell stack structure comprises unit modules (17) comprising a fuel cell(s), a current collecting plate pair, an insulating plate pair, an end plate pair, and fixing bands connecting the end plates; a common distributor (19) providing hydrogen, air, and coolant to the unit modules; and a bus bar (21) electrically connecting the unit modules, and including bus bar body coated with an insulating material, and an insulating cover (71) attached to bus bar heads.    USE - For use in cars.    ADVANTAGE - Fuel cell stack has improved fluid-tightness, structural stability, and electrical stability. Fixing bands along with end plates rigidly stabilize unit module without electrical leakage. Electrical leakage to the exterior of the fuel stack structure is safely prevented.    DETAILED DESCRIPTION - Fuel cell stack structure comprises unit modules comprising a fuel cell(s), a current collecting plate pair, where each current collecting plate is respectively disposed at opposite sides of the fuel cell, an insulating plate pair, where each insulating plate is respectively disposed at a distal side of each current collecting plate, an end plate pair, where each end plate is respectively disposed at a distal side of each insulating plate, and fixing bands connecting the end plates; a common distributor providing hydrogen, air, and coolant to the unit modules; and a bus bar electrically connecting the unit modules, and including a pair of bus bar heads disposed at both ends of the bus bar and bent in a first direction, a bus bar body connecting the bus bar heads, and an insulating cover attached to the bus bar heads. The bus bar body comprises a pair of separate parts coupled by connecting bolts. It is coated with an insulating material. An INDEPENDENT CLAIM is included for a method of stacking fuel cells in a structure.    DESCRIPTION OF DRAWING(S) - The figure shows an external view of a fuel cell stack.    Unit modules (17)    Common distributor (19)    Bus bar (21)    Insulating cover (71)    Hole covers (79)