A rechargeable battery including: an electrode assembly; a case containing the electrode assembly; a cap plate covering an opening of the case; a terminal extending outside the cap plate; a lead tab connecting the electrode assembly to the terminal; and a retainer coupled to the lead tab inside the case and arranged between the lead tab and the case, the retainer including an insertion guide facing away from the electrode assembly and being inclined toward the electrode assembly in a direction extending away from the cap plate.