An integral cap assembly comprising a top cap mounted as a base plate to an opening of a battery can and a cap subassembly including a protective circuit module and the like integrally mounted on the top cap, a method for manufacturing a secondary battery comprising the same, and a secondary battery manufactured thereby are disclosed. The cap assembly is provided as an integral member comprising the top cap acting as the base plate, and the cap subassembly having the protective circuit module provided thereon, thereby simplifying a manufacturing process of the battery while minimizing frequency of defective products. Additionally, the integral cap assembly is manufactured through insert injection molding, thereby providing notable advantages over the conventional technology.