To provide a movable vane axial flow pump capable of setting an extensive driving range and extensive discharge pressure.

An operating shaft 33 is displaced in the shaft center direction by a servo cylinder 38 provided on an end part of the operating shaft 33 by adopting structure to provide a multistage impeller in a pumping channel 27 and to connect movable vanes 32a, 32b constituting the multistage impeller to the operating shaft 33 passed through the inside of a main spindle 28 respectively by links 33a, 34. Consequently, the movable vanes 32a, 32b of the impellers on all stages are made to simultaneously move. It is possible to extend a driving range and to set high discharge pressure by varying vane angles of all the movable vanes of the multistage impeller.