A secondary battery includes: an electrode assembly, a case accommodating the electrode assembly, a cap plate sealing the case and including an inversion plate, an insulation plate including a short-circuit hole corresponding to the inversion plate and a first air hole spaced apart from the short-circuit hole and formed along a top surface of the cap plate, the insulation plate being coupled to the top surface of the cap plate, and a terminal plate coupled to a top surface of the insulation plate and electrically coupled to the electrode assembly. The first air hole is a hole coupling from a top portion of the inversion plate to the outside of the insulation plate.