Problem: To provide: a cell wherein a supporting body is able to have a small open porosity even in cases where the firing temperature is low; a cell stack device; a module; and a module-containing device. Resolution means: A cell (10) according to the present invention is obtained by arranging, on a porous supporting body (1), a porous fuel electrode layer (3), a dense solid electrolyte layer (4) that is formed of a ceramic, and a porous oxygen electrode layer (6) in this order. The amount of Na in the supporting body (1) is 30 x 10 -6 mass% or less. Another cell (10) according to the present invention is obtained by arranging, on a porous supporting body (1) that serves as a first electrode layer, a dense solid electrolyte layer (4) that is formed of a ceramic and a porous oxygen electrode layer (6) in this order. The amount of Na in the supporting body (1) is 30 x 10 -6 mass% or less.