A rechargeable battery according to an exemplary embodiment of the present invention includes: an electrode assembly including a first electrode, a separator, and a second electrode; a case that accommodates the electrode assembly, and of which one side through which the electrode assembly is inserted is opened; a cap assembly provided in the opening of the case by being fixed thereto; a vent hole that is formed in a bottom plate of the case, and of which side walls are multi-stepped; and a vent member provided in the vent, wherein a depth of the vent is greater than a thickness of the bottom plate.