Various embodiments of the present invention relate to a secondary battery. The technical problem to be solved is to provide a secondary battery having an embossed safety vent, which is not damaged by an external force generated during a manufacturing process, can clearly define a rupture area or shape, and makes process management for rupture area or shape easy. To this end, various embodiments of the present invention disclose a secondary battery comprising: a case, a cap plate which is installed in the case and has a vent hole; and a safety vent which is coupled to the vent hole of the cap plate and ruptures when the internal pressure of the case is greater than a reference pressure, wherein the safety vent comprises an embossed portion; and a notch portion formed in the embossed portion.