Lithium ion capacitor

A lithium ion capacitor comprising a positive electrode, a negative electrode and an aprotic organic solvent solution of a lithium salt as an electrolytic solution, wherein a positive electrode active material is a material capable of reversibly supporting lithium ions and/or anions, a negative electrode active material is a material capable of reversibly supporting lithium ions, and the potential of the positive electrode is at most 2.0 V after the positive electrode and the negative electrode are short-circuited, characterized in that each of a positive electrode current collector and a negative electrode current collector has pores penetrating from the front surface to the back surface, the positive electrode and the negative electrode are alternately laminated with a separator interposed therebetween to constitute an electrode unit, the cell is constituted by at least two such electrode units, a lithium ion supply source is disposed between the electrode units, and lithium ions are preliminarily supported by the negative electrode and/or the positive electrode by electrochemical contact of the lithium ion supply source with the negative electrode and/or the positive electrode.