PURPOSE: To obtain a cell which is less deteriorated even during a long-term storage or a long-term discharge period by using a gas-impermeable dense layer composed of a perovskite type oxide or a spinel type oxide as an oxygen ion-conductive positive electrode.

CONSTITUTION: A perovskite type oxide, e.g., La0.8Sr0.2CoO3, is formed by a procedure in which an aqueous solution containing a mixture of the acetates, nitrates, or oxalates of respective metals in a given proportion is evaporated to dryness under reduced pressure, and then the mixed salts thus otained are decomposed by heating in the air and then baked in an oxygen atmosphere. Then, the perovskite oxide is pulverized and then mixed with a dispersant, e.g., methanol, and a binder, e.g., vinyl acetate, to a slurry. Then, the slurry thus obtained is coated on a base film, dried, and then baked to obtain a ceramic sheet which is used as the positive electrode (air electrode)1 for an air-zinc cell.