PURPOSE: To enable a compound material or the like to be conveyed in a non- hardened condition with no reliance on man power by providing a ventilating material between a plate-shaped unit of high rigidity, having many small holes for one sucker surface to communicate with the other surface, and a film-shaped unit coating air-tightly the other surface.

CONSTITUTION: Extending a rope 17 through hanger metal fixtures 16 to be hooked to a hook 18 of a crane, a conveying fixture is horizontally held. And controlling the crane moving the conveying fixture just above a plate material 1 to be conveyed, a sucker plate 3 is piled in its one surface 3a on an upper surface of the plate material 1. Next actuating a vacuum generating device sucking the plate material 1 to the one surface 3a thereafter controlling the crane lifting the conveying fixture to be moved together with the plate material 1, after it arrives at a desired position, a negative pressure condition is released. Here because a ventilating material 13 is contained in a negative pressure chamber 10, a film-shaped unit 9 comes into direct contact with the other surface 3b of the sucker plate 3, as the result, a small hole 4 is prevented from being blocked.