The battery and the electric double layer capacitor

This invention provides a small battery and an electric double layer capacitor exhibiting adequate cell voltage and capacitor withstand voltage. Specifically, this invention provides a battery or electric double layer capacitor in which basic cells comprising a pair of electrodes oppositely laminated via the separator, and an electrolyte are packaged in a resin sheet package, wherein the basic cells are laminated in series via a sheet current collector; the sheet current collector extends to an edge of the resin sheet package around the periphery of the basic cells laminated on both sides of the current collector; the sheet current collector is glued or fused to the resin sheet in its edge; and the adjacent basic cells via the sheet current collector are fluid-tightly separated within the resin sheet package.