Various embodiments of the present invention relate to a secondary battery, and the technical problem to be solved is to provide a secondary battery having a cathode terminal-integrated cap plate, which prevents the occurrence of weld defects during welding of a bus bar. To this end, the present disclosure provides a secondary battery comprising: a case; an electrode assembly received in the case; and a cap plate coupled to the case so as to protect the electrode assembly, wherein the cap plate includes a terminal part to which the electrode assembly is electrically connected and which is formed integrally with the cap plate, and the terminal part is thicker than the cap plate.