The invention relates to a knee airbag (10) having a front wall (22) facing the vehicle occupant (24) when inflated, and a rear wall (20) which is opposite the front wall (22) when inflated, wherein the front wall (22) and the rear wall (20) enclose an internal volume (26). A separating element (28) is provided, which extends in the internal volume (26) at a distance from the front wall (22) and from the real wall (20), along the front wall (22) and the real wall (20), and subdivides the internal volume (26) section by section into a rear-side and a front-side volume (30, 32). Either the rear-side volume (13) or the front-side volume (32) forms a continuous flow connection between an end (51) of the knee airbag (10) close to a gas generator and an end (52) remote from the gas generator, while a direct flow connection from the end (51) close to the gas generator to the front-side volume (32) or to the rear-side volume (30) is at least restricted.