A rechargeable battery includes: an electrode assembly including a first electrode and a second electrode; a housing having an open side, the housing accommodating the electrode assembly; a cap assembly including a cap plate for closing and sealing the open side of the housing; a first current collecting member under the cap assembly and connected to the first electrode; a second current collecting member under the cap assembly and connected to the second electrode; and an insulating case joined with the cap assembly, arranged between the cap plate and the electrode assembly, and having grooves at portions thereof respectively corresponding to the first and second current collecting members.