To provide a compact operating device which admits easy maintenance works and can be repaired eventually through replacement of individual members.

A hydraulic cylinder 1 and pump devices 7, 8, 9, 10, 11 constitute one unit formed by means of coupling with possibility of being uncoupled, being equipped with at least one direct type pipeless flange coupling interposed between each pump device and the cylinder 1, wherein the pipeless flange coupling is connects the pump 9 with at least one duct 12 provided on the pump device, and at least one duct 13 installed at the end of the cylinder leads to one of the working chambers, favorably a one installed at the piston end.