A check valve for an air-packing device comprises upper and lower check valve films that are placed between upper and lower packing films that form the air-packing device contour. The check valve can be advantageously used for the air-packing device having a multiplicity of air containers. A common air duct that allows compressed air to flow into each air container through the check valve is formed between the upper and lower check valve films independently from other films such that the check valve can be placed flexibly in the air-packing device. Peeling agents are applied between the upper and lower check valve films to create the common air duct by preventing heat-sealing between the films. Air passages are formed in each check valve between air guide seals and separation seals.