Provided is a cell that has high theoretical voltage and theoretical capacity and is capable of being repetitively charged and discharged. Specifically, the present invention is a cell comprising a positive electrode, a negative electrode and an electrolyte, wherein the cell is characterized in that: the positive electrode contains a positive electrode active material comprising an alkali metallic compound represented by the formula AxOy (A represents an alkali metal atom, x = 0.5 to 2.5, and y = 0.5 to 2.5); the negative electrode contains a negative electrode active material comprising at least one from the group consisting of an alkali metal, tin, titanium, boron, nitrogen, silica, and carbon; and the positive electrode, the negative electrode, and the electrolyte are enclosed.