Provided is a solid oxide fuel battery formed by a fuel battery cell having: a plate-shaped first solid electrolyte; a fuel pole arranged on one surface of the first solid electrolyte and in contact with a fuel gas; and an air pole arranged on the other surface of the first solid electrolyte and in contact with an oxidant gas. The fuel battery cell further includes a cell-following deformation portion which is arranged on at least one of the two sides of the fuel battery cell along a first layering direction of the first solid electrolyte, the fuel pole, and the air pole and which is deformed to follow a deformation of the fuel battery cell in accordance with a physical amount of a thermal expansion ratio difference or a pressure difference.
