The invention comprises a suction housing connected to a negative pressure forming
means to suck in fluids, a suction opening member mounted on the suction housing,
a part of which is caused to contact the surface of an object, and which defines
a pressure-reduced area together with the suction housing and the surface of an
object, and a means for maintaining the distance between the suction housing and
the surface of an object at a predetermined distance, wherein the suction opening
member and the surface of an object where in contact with each other are caused
to be detached from each other partially or entirely due to the increase in the
fluid pressure difference between the inside and the outside of the pressure-reduced
area, resulting in the communication between the inside and the outside of the
pressure-reduced area, allowing the outside fluid to flow into the pressure-reduced area.
