In order to more reliably reduce a time required to pour electrolyte into a battery case, a device for pouring the electrolyte into the battery case is provided with: a closed pressure-reducing chamber; an electrolyte pouring nozzle for pouring the electrolyte into the battery case disposed within the pressure reducing chamber; and an aerating tank for exposing the electrolyte, which is supplied to the electrolyte pouring nozzle, to the pressure within the pressure reducing chamber.