NOVELTY - An electrochemical capacitor has an element (1), a metal casing (10) accommodating the element together with electrolyte solution, and a sealing component. The element has an anode (2) in which a polarizing-electrode layer containing activated carbon as main constituent is formed on a collector, and a cathode (3) in which an electrode layer containing carbon material or silicon as main constituent is formed in a collector which consists of metal foil. The electrode layers face each other, and a separator (4) is interposed between the electrode layers.    USE - Electrochemical capacitor is used for backup power supply of electronic device, hybrid vehicle and fuel-cell vehicle, and used for regeneration or electric power storage.    ADVANTAGE - The electrochemical capacitor has excellent charging/discharging characteristics and low resistance. The electrode layer has excellent adhesion intensity and retainability.    DETAILED DESCRIPTION - An electrochemical capacitor has an element (1), a metal casing (10) accommodating the element together with organic type electrolyte solution containing lithium ion (Li+), and a sealing component which sealed opening of the metal casing. The element has an anode (2) in which a polarizing-electrode layer containing activated carbon as main constituent is formed on a collector which consists of metal foil, and a cathode (3) in which an electrode layer containing carbon material or silicon as main constituent is formed in a collector which consists of metal foil. The electrode layers face each other, and a separator (4) is interposed between the electrode layers. The electrode layer is formed within a foamed-metal foil, while using the foamed-metal foil which does not form an alloy with lithium as a collector of the cathode.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the electrochemical capacitor. (Drawing includes non-English language text)    Element (1)    Anode (2)    Cathode (3)    Separator (4)    Metal casing (10)