PURPOSE: To maintain the suction state of a work with high precision by allowing a suction hole in a sliding shaft to communicate to a generating source for negative pressure and pressure in a base when suction pad at the top edge of a sliding shaft contacts a holding object article and retracts in the base direction.

CONSTITUTION: A suction pad device 1 is positioned over a work 4, and lowered, and the work 4 and a suction pad 5 are attached, and then the suction pad device 1 is lowered. Then, a sliding shaft 3 rises, and a suction hole 8, piping 6, and a negative pressure generating source communicate through the suction pad 5. The workpiece 4 is adsorbed by applying the negative pressure. The rise of the sliding shaft 3 due to the negative pressure is prevented by the friction of an O-ring 9. The suction pad 1 is raised, and the sliding shaft 3 does not lower because of the O-ring 9 even during the transport of the work 4. After the transport of the work 4, the negative pressure generating source is cut off, and the suction of the work 4 is suspended. The the suction pad device 1 is raised, and then returned to an original point position, and the suc tion pad 5 is lowered by applying a strong pressure, and one cycle is completed.