A hydraulic power unit consists of a hydraulic pump, driving electric motor, oil tank, directional valve, throttle valve, and relief valve, forming a hydraulic power source device or a hydraulic system that includes control valves. It supplies oil according to the flow direction, pressure, and flow rate required by the driving unit, suitable for various machines where the driving unit is separated from the hydraulic power unit (cylinder or motor). By connecting the hydraulic power unit to the driving unit (cylinder or motor) with oil pipes, the hydraulic system can perform various specified actions.