The battery of the invention has a positive-electrode layer 20, a negative-electrode layer 50, and an electrolytic layer 40 through which ionic conduction is performed between the two electrode layers. In this battery, the positive-electrode layer 20 and the negative-electrode layer 50 are laminated with each other and an insulating layer 30 is placed between the positive-electrode layer 20 and the negative-electrode layer 50. The insulating layer 30 has an area smaller than that of one of the positive-electrode layer 20 and the negative-electrode layer 50 and larger than that of the other. There is no place where the positive-electrode layer 20 and the negative-electrode layer 50 face each other through only the electrolytic layer 40. Even when the electrolytic layer 40 has a pinhole, the presence of the insulating layer 30 between the positive-electrode layer 20 and the negative-electrode layer 50 can suppress short-circuiting between the positive- and negative-electrode layers.
