A battery cell degassing apparatus for degassing a battery cell having a gas pocket, comprising: a chamber cover to which the battery cell is detachably placed; a vacuum chamber coupled to the chamber cover as the chamber cover slides in a vertical direction and configured to accommodate the battery cell in a vacuum environment; 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 discharge a gas inside the battery cell to the outside of the battery cell, wherein the piercing unit includes: a first piercing part provided at a left side of the gas pocket inside the vacuum chamber and included a perforating element that perforates a part of the gas pocket; and a second piercing part disposed to face the first piercing part with the gas pocket being interposed therebetween, and included a perforation support disposed to face the perforating element with the gas pocket being interposed therebetween to support the perforating element when the perforating element performs perforation, and the first piercing part and the second piercing part include vacuum pads (327, 367) vacuum-adsorbable to the gas pocket and lifting the gas pocket to both sides. a chamber cover to which the battery cell is detachably placed; a vacuum chamber coupled to the chamber cover as the chamber cover slides in a vertical direction and configured to accommodate the battery cell in a vacuum environment; 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 discharge a gas inside the battery cell to the outside of the battery cell, wherein the piercing unit includes: a first piercing part provided at a left side of the gas pocket inside the vacuum chamber and included a perforating element that perforates a part of the gas pocket; and a second piercing part disposed to face the first piercing part with the gas pocket being interposed therebetween, and included a perforation support disposed to face the perforating element with the gas pocket being interposed therebetween to support the perforating element when the perforating element performs perforation, and the first piercing part and the second piercing part include vacuum pads (327, 367) vacuum-adsorbable to the gas pocket and lifting the gas pocket to both sides. a first piercing part provided at a left side of the gas pocket inside the vacuum chamber and included a perforating element that perforates a part of the gas pocket; and a second piercing part disposed to face the first piercing part with the gas pocket being interposed therebetween, and included a perforation support disposed to face the perforating element with the gas pocket being interposed therebetween to support the perforating element when the perforating element performs perforation, and the first piercing part and the second piercing part include vacuum pads (327, 367) vacuum-adsorbable to the gas pocket and lifting the gas pocket to both sides.