A battery pack is provided and includes a battery module that has a plurality of stacked battery cells and an end cover disposed on an outer side to face an outermost battery cell. A case having a receiving space accommodates the battery module and the receiving space has a side wall facing the end cover. A surface pressure patch is disposed between the end cover of the battery module and the side wall which are disposed in the receiving space, and is configured to apply a pressure to an inside of the battery module when an interval between the end cover and the side wall is closer to a predetermined interval due to swelling of the battery cell.