A secondary battery according to the present invention includes a polymer cell in which insulating wing portions are provided on lead tabs and a top case assembled to the polymer cell and having an evasion portion to reduce interference with the insulating wing portions. A secondary battery can reduce interference which occurs between an insulating wing portion having an irregular shape. Further, as a result, it is possible to reduce the variance of the external dimension of an inner pack and achieve a more stable manufacturing process of the inner pack, and increase the reliability and competency of the inner pack to which the polymer cell is applied.