A secondary battery capable of improving battery characteristics is provided. The secondary battery includes a cathode 21 containing a cathode active material capable of inserting and extracting an electrode reactant, an anode 22 containing an anode active material capable of inserting and extracting the electrode reactant, and an electrolyte containing a solvent and an electrolyte salt. At least one of the cathode 21, the anode 22, and the electrolyte contains a radical scavenger compound. The radical scavenger compound is a compound in which a group having a radical scavenger function exists as a matrix, to which one or more carboxylic metal bases or one or more sulfonic metal bases are introduced. Chemical stability of the cathode 21, the anode 22, or the electrolyte containing the radical scavenger compound is improved. Thus, at the time of charge and discharge, decomposition reaction of the electrolytic solution is easily inhibited.