Secondary battery with insulating member

The present invention provides a rechargeable battery including an electrode assembly performing charges and discharges, a case housing the electrode assembly, a cap plate closing and sealing the case, a terminal mounted on the cap plate and electrically connected to the electrode assembly, and an insulating member installed between the electrode assembly and the case in order to easily install the insulating member and maintain uniform interface of the electrode assembly. The insulating member includes a base closely attached to the bottom of the case, a first insulating plate expanded from the first end of the base, and a second insulating plate expanded from the second end of the base.