PURPOSE: To form the whole body of a device of which elevation bed is driven to elevate by combination of an input device and a toggle mechanism light and compact, and facilitate repairing and inspection of the input device.

CONSTITUTION: A drive device 7 to drive an elevation bed 16 to elevate is composed of a toggle mechanism 7a, and a hydraulic cylinder 7b as an input device to drive a retraction shaft 7a of it, and the toggle mechanism 7a is composed of a pair of oscillation arms 72 disposed in parallel to each other, and a pair of oscillation arms 73 extended from a pair of support point shafts 7f included in a lower base B. As the retraction shaft 71 connected to an output shaft of the hydraulic cylinder 7b advances, oscillation support points of the oscillation arms 72, 73 get apart from each other vertically, so the elevation bed 16 is driven up along guide shafts 15, 15. By disposing the input device 7b of the toggle mechanism 7a at a side part of the elevation bed 16, repairing and inspection of it are facilitated.