Provided is a fuel cell capable of reducing the size thereof by reducing the installation space. The fuel cell includs a plurality of cell tubes, a lower tube plate fixing one end portion of the plurality of cell tubes, a gas flow path portion communicatively connected to an electric power generating chamber through the lower tube plate, a fuel discharge header and an air supply passage provided in the gas flow path portion, in which the fuel discharge header is communicatively connected to an interior of the cell tubes on one surface side and is adjacent to the air supply passage on the other surface and a side surface with a metal member interposed therebetween.