To provide a fixture device for screw fastening work capable of easily moving a nut runner, i.e., a fastening tool to a fastening position when the fastening work of various kinds of arms of a suspension system is performed at a lower part of a vehicle body.

Movable parts 12, 14, 16, 18, 20, 20', 22, 26, 28, 30 are provided on a support part 10 provided in standing manner toward a bottom surface part of the vehicle body conveyed through an overhead hanger movably in a lateral direction, a vertical direction and a height direction of the vehicle body. A fastening part 40 for performing the fastening work of chassis parts relative to the bottom surface part of the vehicle body; load compensation parts 24, 24a for compensating the load of the fastening part at ascending or descending of the fastening part toward the bottom surface part of the vehicle body; a tilt part for adjusting a fine position at position movement of the fastening part; and a reaction force restriction part for supporting reaction force generated at operation of the fastening part are provided on the movable part.