Disclosed herein is a secondary battery having a loop antenna, wherein the loop antenna is patterned on a protection circuit board, which is mounted or attached to a battery cell such that the protection circuit board can be electrically connected to the battery cell, for transmitting and receiving radio frequency signals. In the secondary battery according to the present invention, the loop antenna for transmitting and receiving radio frequency signals is patterned on the protection circuit board, which is mounted or attached to the battery cell. Consequently, the generation of noise in the flexible printed circuit board (FPCB) or liquid crystal display (LCD) signal of a device, in which the secondary battery is mounted, is effectively prevented, and interference due to the generated noise is greatly reduced. Furthermore, no additional space for the installation of the loop antenna is necessary, whereby the reduction in the size, especially, the thickness, and the weight of the secondary battery is accomplished. Also, the conventional expensive outer-type loop antenna is not used, and therefore, the manufacturing costs of the secondary battery can be greatly reduced. The secondary battery with the above-stated construction according to the present invention is preferably used for the inner pack-type secondary battery.