ALKALI BATTERY

The opening portion of a battery case 1 is sealed with a sealing plate 7 using a gasket 5. The potential of electrolytic manganese dioxide in a positive electrode active material is in the range from 275 to 320 mV. The volume of a closed space formed between the gasket 5 and positive and negative electrodes 2 and 3 in the battery case 1 is in the range from 2.0 to 6.0% of the volume inside the battery formed by the battery case 1 and the sealing plate 7.