A pump device includes a flow control valve that returns a part of working fluid discharged from a pump to the suction side, and the flow control valve includes a valve body, a first fluid pressure chamber that is provided so as to face against a first-side end surface of the valve body and that is communicated with a discharge channel, a second fluid pressure chamber that is provided so as to face against a second-side end surface of the valve body and that is communicated with the discharge channel, a biasing member that is accommodated in the second fluid pressure chamber for biasing the valve body in the valve-closing direction, and a pressure regulator that is provided in a communicating passage through which the discharge channel is communicated with the second fluid pressure chamber and that adjusts pressure in the second fluid pressure chamber.