A method for regenerating an end of life (EOL) cell which comprises an electrode assembly including a cathode, an anode, and a separator interposed between the cathode and the anode, wherein the EOL cell is left under a high temperature environment of 80° C. or higher for a predetermined time while pressure is applied thereto, whereby gas located within the electrode assembly is moved to the outer portion of the electrode assembly is provided. The method can regenerate an EOL cell in a simple and economical way without breaking or damaging the same, and furthermore can also be applied to a pack or module which is an extended unit of the cell. A pressuring jig is also provided.