An electric double layer capacitor is composed of a pair of current collectors, a positive polarizable electrode provided on one of the pair of current collectors, a negative polarizable electrode provided on the other of the pair of current collectors, a separator between the positive and negative polarizable electrodes, and an organic electrolytic solution which impregnates at least the positive and negative polarizable electrodes and the separator. The capacitor has a theoretical amount of ions Qt defined as Qt (moles)=C×V÷96,500, wherein C is the rated capacitance (farads) of the capacitor and V is the rated voltage (volts), and an amount of ions Qe in the organic electrolytic solution, such that Qe/Qt=1.7 to 3.5. The capacitor has a high voltage rating, excellent cycle characteristics during high-current charging and discharging, and a low internal resistance in low-temperature environments.