A method of testing a secondary battery includes first to fourth steps. At the first step, the secondary battery after manufacture is charged to a first voltage. At the second step, a second voltage lower than the first voltage is set as a target voltage and discharge or charge is performed in a constant-current constant-voltage mode before the secondary battery is left standing. At the third step, the open circuit voltage of the secondary battery is measured before and after the secondary battery is left standing. At the fourth step, it is determined whether the secondary battery is a conforming item or not based on the difference in the open circuit voltage before and after the secondary battery is left standing.