PURPOSE: To improve dynamic traveling performance by flexibly supporting a cross beam for a rear axle.

CONSTITUTION: This rear axle has a cross beam 1 installed on a car body 2 to be capable of turning around a virtual axis 3 positioned at an intersection of a vertical direction center surface of a vehicle with a vertical surface passing a rear wheel axis or on the back of the intersection, the cross beam 1 is connected to the car body 2 by an elastic connection system, and the connection system comprises two first elastic connection devices 5 positioned forward the rear wheel axis, and two second elastic connection devices 7 symmetrically positioned to the vertical direction center surface of the vehicle on the back of a rear wheel or at its level. In the rear axle, the first elastic connection device 5 has a flexible device, the flexible device is interposed between the car body 2 and the cross beam 1, it gives a relatively large flexibility to the connection device in the tangential direction of the virtual axis 3, and it provides a small flexibility in the radial direction.