An “electric double-layer capacitor” is a capacitor that utilizes the phenomenon called electric double layer whereby electricity is stored where a solid and a liquid come into contact. Concretely, the structure of an electric double-layer capacitor involves two electrodes made by forming active carbon into thin sheets that are separated by a semi-permeable membrane called a separator and placed in an electrolyte solution such as diluted sulfuric acid. The electrodes are subjected to a low voltage (about 0.8 volts) that does not cause electrolysis of electrolyte, this therefore results in ions rapidly being stored on the surface of the active carbon. The active carbon has an extremely large surface area of between 1,000 and 2,000 square meters per gram, which allows the absorption of a large number of ions. In fact, the capacity reaches 1 farad, that is, 100 thousand times the capacity of normal capacitors. Utilizing this principle, "Super capacitor" was developed by NEC more than 20 years ago and is currently used as the backup electric power source for clocks in VCRs and other appliances. While on the one hand "Super capacitor" has a very large internal resistance and is only capable of allowing currents of between several tens of micro-amperes to 1 milli-ampere to flow, on the other, it exhibits superior characteristics in continued storage of electricity (self-discharge characteristics) and is appropriate for applications in which a discharge time of 100 hours or more is required. As the capacitor recharges when the equipment is plugged into an electric outlet, there is no need for replacement such as in the case of batteries, and for this reason, "Super capacitor" was ideal as a backup electric power source. However, there had been the great hope that the electric double-layer capacitor, capable of storing a large amount of electricity, would fulfill the more significant and fundamental function of a capacitor, that is, to support instantaneous peak electric current occurrence on equipment. NEC TOKIN have been consistently working on developing "SuperCapacitor" with reduced internal resistance in order to address such potential capability.