A terminal unit of a secondary battery and a method of manufacturing the same, the terminal unit including an electrode rivet, the electrode rivet being connected to an electrode assembly; a rivet terminal, the rivet terminal including a metal different from a metal of the electrode rivet; and a medium plate, the medium plate including a same metal as the electrode rivet, and being disposed between the electrode rivet and the rivet terminal so as to be overlap-weldable to the rivet terminal.