Abstract: The present invention provides a secondary battery using a liquid electrolyte excellent in storage characteristics. The secondary battery includes a cathode, an anode, and a liquid electrolyte, where the cathode and the anode contain at least one mutual active material. This symmetrical electrode configuration, that the at least one active material for the cathode and the anode is mutual, enables equalization of an electrode electric potential difference before charge or after discharge; and thus electrolyte degradation is efficiently restrained to improve storage characteristics.