The present invention provides a battery cell capable of uniformly holding an electrode laminate and speeding up a manufacturing process. A battery cell includes an electrode laminate including positive and negative electrodes and an electrolyte layer, in which the positive and negative electrodes are alternately laminated with the electrolyte layer interposed between them; and a tube-shaped insulating member that is heat-shrinkable and holds the electrode laminate, wherein the insulating material has at least two folded parts for positioning a member disposed in the internal space of the insulating member. The insulating member preferably has two portions each between the two folded parts, and the two portions are preferably equal in circumferential length.