NOVELTY - The flat-tubular solid oxide cell stack comprises unit cells (110) of which each comprises an anode including a first-gas flow channel (112), a cathode deposited on an electrolyte layer coated on the anode and an interconnection material deposited opposite to a surface having the cathode. The unit cell consists of: a unit cell in which connection holes (120) passing through both sides of the cell, respectively, are formed at portions near both ends of the first-gas flow channel in a thickness direction of the cell and are formed in directions opposite to each other.    USE - The flat-tubular solid oxide cell stack is useful as a fuel cell such as an alkali fuel cell, a phosphoric acid fuel cell, a molten carbonate fuel cell, a solid oxide fuel cell and a polymer electrolyte fuel cell and a high-temperature electrolyzer.    ADVANTAGE - The flat-tubular solid oxide cell stack has increased electrical energy generation efficiency and low pollution rate, and generates hydrogen with high purity.    DETAILED DESCRIPTION - The flat-tubular solid oxide cell stack comprises unit cells (110) of which each comprises an anode including a first-gas flow channel (112), a cathode deposited on an electrolyte layer coated on the anode and an interconnection material deposited opposite to a surface having the cathode. The unit cell consists of: a unit cell in which connection holes (120) passing through both sides of the cell, respectively, are formed at portions near both ends of the first-gas flow channel in a thickness direction of the cell and are formed in directions opposite to each other so as to be the first-gas flow channels of the cells; a unit cell in which a hole passing through both sides of the cell is formed at a portion near one end of the first-gas flow channel in the thickness direction of the cell and a connection hole passing through the upper side of the cell is formed at a portion near the other end in the thickness direction of the cell, where the connection holes are connected with the first-gas flow channels of the cells; a unit cell in which a hole passing through both sides of the cell is formed at a portion near one end of the first-gas flow channel in the thickness direction of the cell and a connection hole passing through the lower side of the cell is formed at a portion near the other end in the thickness direction of the cell, where the connection holes are connected with the first-gas flow channels of the cells; and a unit cell in which connection holes passing through both sides of the cell are formed at portions near both ends of the cell in the thickness direction of the cell so as to be connected with the first-gas flow channels of the cells. The unit cells are continuously connected to each other by the connection holes in the thickness direction. A sealing unit having a ring-shaped sealing material is formed outside of the connection holes, which communicate with the first-gas flow channels of the unit cells of the cell stack so as to seal gas.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a flat-tubular solid oxide cell stack.    Unit cells (110)    First-gas flow channel (112)    Second-gas flow channel (113)    Connection hole (120)    First-gas inlet manifold. (140)