To increase the withstand voltage and reduce deterioration of characteristics which is caused by charge and discharge cycle, by mixing copper or nickel in carbon material of the negative pole of an electric double layer capacitor which can occlude and desorb lithium ions.

An electric double layer capacitor is provided with a positive pole composed of a polarizable electrode whose main body is active carbon, a negative pole, and organic electrolyte using lithium salt as solute. The negative pole contains carbon material capable of occluding and desorbing lithium ions, and copper and nickel. Lithium ions are occluded by a chemical method or an electrochemical method. As to the carbon material capable of occluding and desorbing lithium ions, the spacing of the [002] face which is measured by using X ray diffraction is set as 0.335-0.410 nm. The contents of copper or nickel in the negative pole is 5-50 wt.%, and the powder having an average grain diameter of 0.1-50 μm are added to the negative pole. C+/C- of the electric double layer capacitor is set as 0.001-0.9.