A secondary battery is disclosed. In one aspect, the secondary battery includes a case accommodating an electrode assembly, a cap plate sealing an opening of the case, an electrode terminal electrically connected to the electrode assembly and disposed over the cap, and an insulating member provided between the cap plate and the electrode terminal and configured to insulate the electrode terminal from the cap plate. The battery also includes a connection tab disposed over the electrode terminal, and a safety device having a portion positioned under the connection tab and electrically connected to the electrode terminal via the connection tab. The safety device has at least one of electric conductivity and thermal conductivity greater than that of the connection tab, and at least a part of the safety device is seated on the insulating member.