PURPOSE: To drive a plurality of driven units by a hydraulic pump for feeding conductive hydraulic oil by an electromagnetic force for operating the hydraulic oil.

CONSTITUTION: An electric field and a magnetic field are operated at conductive hydraulic oil in a plurality of pipes 17a bundled by a pump body 17 to feed the oil to driven units 13, 14 connected to the pipes 17 by electromagnetic force, thereby freely controlling discharge flow rate and pressure of the oil flowing in the pipes 17a in response to intensities of the electric field and the magnetic field. Thus, the units 13, 14 having different required driving forces are freely and suitably driven without using a particular hydraulic circuit, pressure interference generated between the plurality of driven units 13, 14 is eliminated, and the plurality of the driven units 13, 14 can be smoothly driven similarly to the case of driving solely the units even at the time of simultaneously driving the plurality of the units.