PURPOSE: To obtain an efficient pump, by employing an internal gear in main section of a pump thereby forming an internal gear pump at the inside thereof and a vane pump at the outside thereof.

CONSTITUTION: Main section of a pump is constructed with internal gears 1, 2 so as to form a sub-pump, i.e. an internal gear pump, together with inside suction/discharge ports 5, 6, while a vane 7 is arranged at the outer circumference of an external gear 1 so as to form a main pump, i.e. a vane pump, together with the outside suction/discharge ports 3, 4. Since the delivery flow reaction produced by the vane pump is reduced by the difference of axes of the internal gears 1, 2, necessary input capacity of a complex pump comprising an internal gear pump and the vane pump can be reduced.