The present invention provides an electrochemical capacitor, which includes: a cell electrode unit which includes cathodes, anodes, and separators interposed between the cathodes and the anodes which are alternately stacked in multiple layers; cathode terminals which are extended to one side of each of the cathodes and are stacked one above another; anode terminals which are extended to one side of each of the anodes and are stacked one above another with a separation space from the cathode terminals; a housing for receiving the cell electrode unit, the cathode terminals, and the anode terminals; and an output terminal unit which is insert-molded to penetrate from the inside to the outside of the housing, electrically connected to at least one of each of the stacked cathode and anode terminals, and immobilizes the cell electrode unit into the housing.