A battery pack and method of manufacturing same are provided. The battery pack can stabilize bending of a lead housed in a space defined by an external package. Leads 2, 3 of a battery element are bonded to a circuit board housed in a top cover 6. A holder 11 is mechanically fitted to the top cover 6, made of resin molded material and produced by injection molding, for example. The edge faces of ribs 12a, 12b, 12c formed on the holder 11 serve as planes which receive the circuit board 4 in the top cover 6. The top cover 6 and the holder 11 fitted to each other are turned 90°, and moved toward the opening in the edge face of the cell 1 while bending the leads 2, 3, which are bent along the contours of both the sidewalls and bottom surface of the holder 11 and housed in a space defined by the external package. The circumferential surface of the top cover 6 is bonded by heat to the inner surface of the external package.