NOVELTY - The cell (10) has a partition unit for fixing an end portion of fuel cell tubes (12). A gas flow path portion i.e. support frame (30), is communicatively connected to an electric power generating chamber (17) through the partition unit. Spaces are provided in the gas flow path portion. One of the spaces is communicatively connected to an inside of the fuel cell tube on a surface side and provided adjacent to the other space, where a metal unit is interposed between the spaces on another surface side and a side surface (31). The latter space is communicatively connected to the chamber.    USE - Solid oxide fuel cell for generating electric power.    ADVANTAGE - The design of the cell allows forming a space for an air supply header so as to uniformly supply air from the air supply header to the power generating chamber, thus preventing or suppressing a temperature distribution and an oxygen concentration distribution from occurring in the power generating chamber for evenly distributing oxidant inside the power generating chamber, and hence efficiently generating electric power, preventing damage caused by low oxygen concentration, and improving reliability and durability of the cell. The space is communicatively connected to the inside of the fuel cell tube on the surface side and provided adjacent to the other space with the metal unit interposed between the spaces on the surface side and the side surface, thus eliminating a need for an oxidant supply pipe and a fuel gas discharge pipe from the side surface of the cell, and hence reducing installation space by a narrowing space between the adjacent cells.    DETAILED DESCRIPTION - The partition unit is an upper tube plate (13) or lower tube plate (14). The spaces are a fuel discharge header (20) and an air supply passage (40). An INDEPENDENT CLAIM is also included for an oxidant supply method for introducing fuel gas from a fuel supply chamber to an inside of a fuel cell tube to be discharged to a fuel discharge chamber.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic longitudinal sectional view of a solid oxide fuel cell with enlarged representations of an upper heat insulator, a lower tube plate and a support frame.    Solid oxide fuel cell (10)    Fuel cell tube (12)    Upper tube plate (13)    Lower tube plate (14)    Electric power generating chamber (17)    Fuel discharge header (20)    Support frame (30)    Side surface (31)    Air supply passage (40)