Disclosed herein is a secondary battery pack including an anode terminal and a cathode terminal of a battery cell connected to a protection circuit module (PCM), the anode terminal and the cathode terminal of the battery cell being made of plate-shaped conductive members, the battery cell having the anode terminal and the cathode terminal formed at one end thereof, the battery cell having a thermally bonded surplus part formed at the end thereof at which the anode terminal and the cathode terminal are formed, and the PCM including a protection circuit board (PCB) having a protection circuit formed thereon, an external input and output terminal connected to the protection circuit of the PCB, and an electrically insulative PCM case configured to have a hollow structure in which the PCB is mounted, the PCM case being provided with a slit, through which the electrode terminals of the battery cell are inserted, the PCM being loaded on the thermally bonded surplus part of the battery cell in a state in which the PCM is electrically connected to the battery cell.