NOVELTY - A fuel cell having a unit cell (10) comprises an electrolyte electrode assembly (12) that includes anode (26), cathode (30) and a solid electrolyte (28) interposed between anode and cathode; a pair of separators (14, 16) sandwiching the assembly and a buffer layer precursor for a buffer layer (22, 24) interposed between at least anode and one of the separators or between the cathode and other separators. The buffer layer precursor (18, 20) includes inorganic powder having an electron conductivity, and plastically deformed organic material.    USE - As a fuel cell (claimed) useful for power generation.    ADVANTAGE - The fuel cell includes electrodes and separators having large surface areas, resulting in good current collection efficiency, at the same time there is no concern of damages in the electrodes having large surface areas, as the warpage/waviness of the electrolyte electrode assembly and the separators are suitably absorbed, and the buffer layers tightly contacts the electrolyte electrode assembly and the power generation areas of the separators. Thus, the desired current collection efficiency is maintained, and thus improvement in the power generation characteristics of the fuel cell is achieved. The method of producing the fuel cell is easy. By providing the buffer layer precursor between the separator and the electrode, a fuel cell having good current collection efficiency and power generation characteristics is obtained. As the buffer layer precursor is plastically deformable by weights of the separators and the electrolyte electrode assembly when the separators and the electrolyte electrode assembly are stacked together to form the unit cell. In this case, simply by forming the unit cell, the buffer layer precursor can be deformed plastically easily, and operation of producing the fuel cell becomes considerably easy.    DETAILED DESCRIPTION - A fuel cell having a unit cell (10) comprises an electrolyte electrode assembly (12) that includes anode (26), cathode (30) and a solid electrolyte (28) interposed between anode and cathode; a pair of separators (14, 16) sandwiching the assembly and a buffer layer precursor for a buffer layer (22, 24) interposed between at least anode and one of the separators or between the cathode and other separators. The buffer layer precursor (18, 20) includes inorganic powder having an electron conductivity, and plastically deformed organic material. The buffer layer precursor fills clearance between the anode or the cathode and a power generation area of one of the separators so as to tightly contact both of the anode or the cathode and the power generation area of the one of the separators; and the organic material disappears when the unit cell is used for power generation reaction. An INDEPENDENT CLAIM is included for a method of producing a fuel cell involving mixing inorganic powder having an electron conductivity and an organic material to obtain a slurry; forming a sheet of a buffer layer precursor for a buffer layer using the slurry; producing the fuel cell having the unit cell including the buffer layer precursor and plastically deforming the buffer layer precursor to fill clearance between the anode or the cathode and a power generation area of one of the separators for allowing the buffer layer precursor to tightly contact the anode or the cathode and the power generation area of the one of the separators.    DESCRIPTION OF DRAWING(S) - The figure shows a longitudinal sectional view schematically showing the entire unit cell of a fuel cell.    Unit cell (10)    Electrolyte electrode assembly (12)    Separators (14, 16)    Buffer layer precursor (18, 20)    Buffer layers (22, 24)    Anode (26)    Solid electrolyte (28)    Cathode (30)