CELL STACK DEVICE, MODULE, AND MODULE HOUSING DEVICE

A cell stack in which a plurality of cells 1 is aligned; and a manifold to which one ends of the plurality of cells 1 are fixed by a sealing material 8, and configured to supply reaction gas to the plurality of cells 1 are provided. Each of the plurality of cells 1 includes a support substrate 2 having a length direction; an element part a in which a fuel electrode layer 3, a solid electrolyte layer 4, and an air electrode layer 5 are laminated on the support substrate 2; and a middle layer 21 including a first middle layer 21a arranged between the solid electrolyte layer 4 and the air electrode layer 5, and is bonded to the solid electrolyte layer and a second middle layer 21b having a thickness that is larger than a thickness of the first middle layer, and is bonded to the air electrode layer 5. The sealing material is provided to one of the solid electrolyte layer 4 and the first middle layer 21 at the one end of each of the cells 1 to fix the plurality of cells 1 to the manifold 7.