Secondary Battery

A secondary battery according to the present invention comprises: an electrode assembly in which a first electrode, a separator, and a second electrode are alternately stacked and wound together; a can provided with an accommodation part that accommodates the electrode assembly therein, the can comprising a first can and a second can, which have cylindrical shapes opened in a direction facing each other; and an insulator configured to insulate an overlapping portion between the first can and the second can. The first can forms a first electrode terminal that directly contacts an end of the first electrode, and the second can forms a second electrode terminal that directly contacts an end of the second electrode.