(EN) A battery pack which can be used under a large current load safely by increasing the area of an incorporated PTC layer and reducing the internal resistance of the PTC layer and a PTC element are disclosed. The battery pack is provided with a plurality of unit cells (1) horizontally arranged side by side and a PTC element (P) which protects the unit cells (1) from excessively large current. First and second electrodes (3 and 4) are respectively connected to both sides of the PTC layer (2) of the PTC element (P). The PTC layer (2) is so formed as to cover almost all the end faces of the two unit cells (1) connected with the first and second electrodes (3 and 4) and has through holes (2B) at the positions corresponding to the end-section electrodes (1A) of the unit cells (1). The first and second electrodes (3 and 4) have nearly the same shape as the PTC layer (2), and the portions of the electrodes (3 and 4) at the through holes (2B) of the PTC layer (2) are connected to the end-section electrodes (1A) of the unit cells (1).
