The invention concerns an artificial leg with an artificial knee having, for carrying a femoral stump, a joint body which is rotatable about the joint axis; with a shaft, the upper end of which engages the joint body, and the lower end of which bears an artificial foot; joint body and shaft cooperate in such a way that a rotational movement of the joint body is transferred into a translative movement of the shaft, and that during the bending of the knee joint the distance between its joint axis and the tip of the artificial foot is reduced.