To improve the riding comfort of an automobile by effectively softening an impact force, which is to be applied to the car body from the wheel side, by a coil spring which is inserted between a suspension arm bearing the wheel and the car body.

The coil spring 12 is inserted between mutual facing sections 10 and 11 of a section of the car body 1 and the swinging section of the suspension arm 6. One end surface 23 and the other end surface 24 in the longitudinal direction of the coil spring 12 are respectively bonded to the mutual facing surfaces of both facing sections 10 and 11. The end sections of the base section side of spring wires on the one end surface 23 and the other end surface 24 of the coil spring 12 are made first and second bonding completed points 27 and 28 for the facing surfaces of the facing sections 10 and 11, respectively. Then, the first and second bonding completion points 27 and 28 are located at approximately the same place to each other in the peripheral direction of the coil central line 13 of the coil spring 12.