A construction machine, comprising: a hydraulic actuator that is operated by hydraulic oil supplied; a tank that stores return oil from the hydraulic actuator ; a flow control valve for making hydraulic oil discharged from the hydraulic actuator flow toward the tank ; and a pressure accumulator that accumulates pressure of the hydraulic oil that flows from the flow control valve toward the tank , wherein there are provided: a first pressure compensation valve that is arranged between the hydraulic actuator and the pressure accumulator and is for controlling difference between front and back pressures of the flow control valve to be kept constant; and a second pressure compensation valve that is arranged between the pressure accumulator and the tank and is for controlling difference between front and back pressures of the flow control valve and the first pressure compensation valve to be kept constant; characterized in that the first pressure compensation valve is arranged on the downstream side of the flow of hydraulic oil discharged from the hydraulic actuator with respect to the flow control valve , and the second pressure compensation valve controls difference between front pressure of the flow control valve and back pressure of the first pressure compensation valve to be kept constant, and a first target differential pressure set for the first pressure compensation valve is equal to or less than a second target differential pressure set for the second pressure compensation valve . a hydraulic actuator that is operated by hydraulic oil supplied; a tank that stores return oil from the hydraulic actuator ; a flow control valve for making hydraulic oil discharged from the hydraulic actuator flow toward the tank ; and a pressure accumulator that accumulates pressure of the hydraulic oil that flows from the flow control valve toward the tank , wherein there are provided: a first pressure compensation valve that is arranged between the hydraulic actuator and the pressure accumulator and is for controlling difference between front and back pressures of the flow control valve to be kept constant; and a second pressure compensation valve that is arranged between the pressure accumulator and the tank and is for controlling difference between front and back pressures of the flow control valve and the first pressure compensation valve to be kept constant; a first pressure compensation valve that is arranged between the hydraulic actuator and the pressure accumulator and is for controlling difference between front and back pressures of the flow control valve to be kept constant; and a second pressure compensation valve that is arranged between the pressure accumulator and the tank and is for controlling difference between front and back pressures of the flow control valve and the first pressure compensation valve to be kept constant; characterized in that the first pressure compensation valve is arranged on the downstream side of the flow of hydraulic oil discharged from the hydraulic actuator with respect to the flow control valve , and the second pressure compensation valve controls difference between front pressure of the flow control valve and back pressure of the first pressure compensation valve to be kept constant, and a first target differential pressure set for the first pressure compensation valve is equal to or less than a second target differential pressure set for the second pressure compensation valve . <EOS>