To provide a support structure of a link part capable of stabilizing the contact of a link part with a small screw washer surface to restrain run-out of the link surface, and reducing the rotating torque of the link part main body and the operating torque of the whole link mechanism to enable smooth operation.

In this support structure, a link lever 15 is supported on the tip of a support shaft 16 by the small screw 17, and a small screw washer 20 for fitting the small screw 17 is provided in the opposite surface to the support shaft 16 in the link lever 15. A surface of the link lever 15 abutting on the small screw washer 20 is provided with annular projections 22A, 22B formed concentrically with the small screw 17, and the tops of the annular projections 22A, 22B are brought into sliding contact with the small screw washer 20. By this structure, the contact of the link lever 15 and the small screw washer surface is stabilized to restrain run-out of the link surface, and the rotating torque of the link lever 15 main body and the operating torque of the whole link mechanism can be reduced.