A battery cell degassing apparatus for degassing a battery cell having a gas pocket, which includes a chamber cover to which the battery cell is detachably mounted, a vacuum chamber coupled to the chamber cover and configured to accommodate the battery cell in a vacuum environment, the chamber cover being slidable in a vertical direction with respect to the vacuum chamber, a piercing unit provided at the vacuum chamber to pierce a part of the gas pocket, and a pressing unit provided at the vacuum chamber to be spaced apart from the piercing unit and configured to flatten a left surface and a right surface of the battery cell and to discharge a gas inside the battery cell to the outside of the battery cell is provided.