To provide a pump capable of regulating a fluid to be discharged to the outside of a pump housing from the other discharge port out of one discharge port and the other discharge port provided in the pump housing, satisfactorily with simple structure when a blade member is rotated within the pump housing in a direction to discharge the fluid from one discharge port.

A blade member 35 rotatable both normally and reversely is provided in a storage space 34, and a fluid passage 47 is formed between an outer peripheral edge 35a of the blade member 35 and a peripheral wall part 31a of a lower pump housing 31. Two discharge ports 45a, 46a are formed at a predetermined space in the peripheral wall part 31a, and projecting wall parts 49, 51 extending toward the peripheral wall part 31a are protrusively provided at a guide regulation part 48 provided between the discharge ports 45a, 46a. Narrow regions 50, 52 having passage cross-sectional areas smaller than the passage cross-sectional areas of the discharge ports 45a, 46a are formed between the fluid passage 47 and the discharge ports 45a, 46a.