To provide a hybrid electric double layer capacitor which has high energy density, can be rapidly charged/discharged and has no cut-off voltage.

In the hybrid electric double layer capacitor having a positive electrode having electrostatic capacity, a negative electrode having redox capacity and an electrolyte containing lithium salt, cations of the lithium salt are subjected to intercalation in the cathode, cations and anions of the lithium salt are subjected to absorbing/releasing in the anode, and a discharge stop voltage is 0 V.