An OPW airbag having warp and weft threads woven together in at least three woven fabric layers: a lower fabric layer, an upper fabric layer, and a middle fabric layer therebetween. The weft threads of the middle fabric layer emerge from the middle fabric layer in a first partial region of the airbag and are tied partially to the upper fabric layer and partially to the lower fabric layer. The warp threads of the middle fabric layer emerge from the middle fabric layer in the first partial region of the airbag and float freely between the lower fabric layer and the upper fabric layer. The weft and warp threads of the middle fabric layer are incorporated into the lower fabric layer or into the upper fabric layer in a second partial region of the airbag or are tied to the lower or upper fabric layer at a few attachment points.