To form a fitting hole for fitting a guide device at the correct position of a floor surface, and to correctly and easily regulate the height position of a suspension door body.

A suspension door is inserted in a traveling groove formed in a lower end face of a suspension door body suspended from an upper rail in a freely traveling manner to achieve the traveling guide in a condition where a guide pin provided on a guide device in a projecting/retracting manner by the magnetic force is projected. An execution jig B for forming a fitting hole is used for forming the fitting hole in the floor surface to embed the guide device. Inking markers 41a, 41b for marking in the longitudinal and transverse directions in the plan view are provided orthogonal to each other on a plate part 40 to constitute a main part of the execution jig B for forming the fitting hole. A guide hole 42 for opening a hole around intersections 41a, 41b of the inking markers in the longitudinal and transverse directions is formed in the plate part.