An airbag includes a first chamber, a second chamber, and a gas flow channel connecting the two chambers. A valve is located inside the gas flow channel allows an unthrottled gas stream from the first chamber to the second chamber when a pressure inside the first chamber is higher than a pressure in the second chamber and blocks or throttles the gas stream through the gas flow channel when the pressure inside the second chamber is higher than in the first chamber. The valve includes a two-layered inlay extending from a first end pointing towards the first chamber to a second end pointing towards the second chamber. The two-layered inlay is connected to the gas flow channel at its first end via at least two connecting points being remote from each other. In order to make the manufacture of the airbag very easy and in order to provide a construction that allows the possibility of a defined throttling of the gas flow in the gas flow direction opposite to the unthrottled gas flow direction, a connection free area in which at least one layer of the two-layered inlay is without connection to the gas flow channel, is provided between the two connecting points and the two layers of the two-layered inlay are at least partially connected to each other in the area of the first end.