Provided is a secondary battery including a hydroxide-ion-conductive ceramic separator. The secondary battery includes a positive electrode; a negative electrode; an alkaline electrolytic solution; a ceramic separator that is composed of a hydroxide-ion-conductive inorganic solid electrolyte and separates the positive electrode from the negative electrode; a porous substrate disposed on at least one surface of the ceramic separator; and a container accommodating at least the negative electrode and the alkaline electrolytic solution, wherein the inorganic solid electrolyte is in the form of a membrane or layer densified enough to have water impermeability, and the porous substrate has a thickness of 100 to 1,800 µm. According to the secondary battery of the present invention, the thickness and resistance of the ceramic separator are decreased without concern for reduced strength, and a reduction in energy density and an increase in internal resistance are effectively prevented.