Inner battery pack and manufacturing

A battery pack, and a method for preparing the battery pack are provided to improve the stability of a battery pack by protecting a protection circuit module against external impact and to increase the lifetime of a battery pack. A battery pack comprises a battery(110) where a first electrode(111) and a second electrode(112) are prepared in one side; a safety device(130) whose one end(131) is welded to the second electrode of the battery; a protection circuit module(150) which has a first terminal(151) welded to the first electrode of the battery and a second terminal(152) welded to the other end(133) of the safety device; and a holder(140) which is engaged to the one side of the battery and mounts the protection circuit module and the safety device to hold them, wherein the aperture for welding the one end of the safety element and the second electrode is formed at the holder.