Abstract: A secondary battery comprised of a positive electrode, a negative electrode and a non-aqueous electrolyte, wherein the positive electrode comprises a sodium-cobalt oxide as the main component, the negative electrode is composed of a composite body comprising a sodium alloy such as a sodium/lead or sodium/tin alloy, a carbon material and a binder, and the non-aqueous electrolyte is composed of a sodium salt and an ether compound. The positive electrode and negative electrode is prepared by a process wherein a binder is swollen with or dissolved in an organic solvent, the swollen or dissolved binder is mixed with a carbon material, and the mixture is then mixed with a sodium alloy or a sodium-cobalt oxide directly or after removal of the organic solvent.