NOVELTY - The device i.e. lithium ion capacitor, has a laminated electrode unit provided with positive and negative electrode sheets. Positive and negative electrode layers are formed on a positive electrode collector (22) and a negative electrode collector (25). Electrolyte solution is accommodated in an exterior container. The positive and negative electrode sheets are electrically connected together such that an end of the collector is protruded to exterior of the container through a metal sheet-like lead component (32) that performs buffer function according to external force.    USE - Electrical storage device i.e. lithium ion capacitor, for moving a body such as motor vehicle and buoy i.e. float. Can also be used as an electrical double layer capacitor and a lithium ion secondary battery.    ADVANTAGE - The positive electrode sheet and the negative electrode sheet are electrically connected together such that the end of the collector is protruded to the exterior of the container through the metal sheet-like lead component that performs buffer function according to external force so as to absorb stress applied to the sheet-like lead component according to vibration absorption ability of the sheet-like lead component. The device can suppress metal fatigue, crack and internal resistance arising in the sheet-like lead component at presence of vibration for long time, so that generation of fracture in the sheet-like lead component can be suppressed. The penetration opening parts are provided with a fine through-hole that is formed in the collector so as to suppress intend thickness-uniform property difficulty of the electrode layer, so that high energy density, high output and low resistance of the electrode layer can be obtained.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view illustrating a state of fixing state of positive and negative electrode collectors with a metal sheet-like lead component.    Positive electrode terminal (18)    Negative electrode terminal (19)    Positive electrode collector (22)    Through-hole (22a)    Negative electrode collector (25)    Metal sheet-like lead component (32)