Abstract: The present invention includes: a reaction tank (1) for immersing an electrode material of a lithium secondary battery into a molten salt of lithium chloride containing metal lithium, so as to perform a reducing reaction of the electrode material with the metal lithium; a movable perforated processing vessel (10) configured to be immersed into the molten salt in the reaction tank (1) together with the electrode material contained therein; and vessel carrying means for immersing the perforated processing vessel (10) containing the electrode material therein into the molten salt of lithium chloride in the reaction tank (1) and pulling up the vessel (10) from the reaction tank (1) after a process has been performed.