PURPOSE: To attach a fixture to a stationary member in a simple attaching procedure which can be performed by one hand, and to reduce the fatigue even in a face-up work.

CONSTITUTION: First locking parts 8 which may be locked in one side edge part 4a in an inwardly widened groove formed in a stationary member K are provided respectively at opposite ends of a first planer type retaining member 6A for supporting a member P to be fixed to the stationary member K. Further, second locking parts 9 which may be locked to the other side edge part 4b in the groove 3 are provided respectively at opposite ends of a second planer type retaining member 6B are provided. A pivotally coupling part 7 couples both retainer members 6A, 6B so that the members 6A, 6B are changed over between an entrance condition in which the first and second locking parts 8, 9 approach together and enter the groove 3, and the first and second locking members 8, 9 are separate from each other and are locked to the groove 3.