A storage battery can inhibit generation of dendritic crystal of metal in cathode active substance and has excellent charge/discharge circulation perfomrance. The storage battery includes a cathode that using metal which is possible to generate the dendritic crystal and/or compounds thereof, an anode, a separator, and an electrolyte comprising an additive, wherein the concentration of hte additive in the electrolyte in the cathode side resion separated by the separator is higher than that in the anode side resion. The separator perferably is a semi-permeable ionic exchange membrane, and the additive perferably is a substance which can enhance the charge/discharge property of the cathode in the storage battery.