A rechargeable battery includes an electrode assembly; a case having an opening and in which the electrode assembly is installed; a cap plate combined to the opening and sealing the case; at least one electrode terminal electrically connected with the electrode assembly; a lower gasket disposed between the cap plate and the electrode terminal, and having an end portion disposed at a lower portion of the cap plate and including a first inclined side forming an acute angle or obtuse angle with respect to a side of the cap plate; and a lower insulating member provided in the case, and having an end portion disposed adjacent to the end portion of the lower gasket in a lower portion of the cap plate and including a second inclined side forming an acute angle or an obtuse angle with respect to the side of the cap plate.