The rectangular battery inserts, in a battery case of airtight structure an electrode group (72) alternately stacking positive electrodes (74) and negative electrodes (73) via separators (75). The battery case has the opened part of a rectangular closed bottom outer container airtightly sealed by a cover. The outermost electrodes (73) located on both faces of the electrode group (72) are electrodes coated with active material on the surface of the core (77). Furthermore, the outermost electrodes (73) are poles of the same polarity and are the core protruding faces which make the core (77) protrude at the surface in contact with the outer container. <IMAGE>
