An embodiment of the present invention is to provide a secondary battery which simplifies a process for connecting an electrode terminal and a lead tap. The secondary battery according to an embodiment of the present invention comprises an electrode assembly charged and discharged; a case accommodating the electrode assembly; a cap plate coupled to an opening part of the case; a lead tap connected to an electrode of the electrode assembly; and an electrode terminal connected to the lead tap by being installed on the cap plate. The electrode terminal includes a column part inserted into a terminal hole of the cap plate; and a flange part formed wider than the cross-section area of the column part at one end of the column part and disposed inside the cap plate. The lead tap includes an insertion part in which the column part is inserted and welded in the inner surface of the insertion while being in contact with the flange part.
