Provided is an efficient method for determining the completion of discharging waste batteries, the method being capable of accurately identifying the discharging states of the charge remaining in the waste batteries and appropriately determining the completion of discharging without measuring the residual voltage of each of the waste batteries. The method for determining the completion of discharging waste batteries according to the present invention is characterized in that after immersing the waste batteries in a conductive liquid, the concentration of hydrogen gas produced from the liquid is measured, thereby determining the completion of discharging the charge remaining in the waste batteries.