PURPOSE: To suppress occurrence of a voltex flow in an overflowing range for improvement in pumping efficiency by forming a front supply passage in a wall member with a suction opening, and spilling fuel from a rear supply passage with a reduced cross section into the front supply passage.

CONSTITUTION: When an impeller 14 rotates, fuel flows from a storage tank only into a rear supply passage 40 formed in a wall member 24 through a suction opening 42. An inflow range 46 formed within a range in the peripheral direction of the suction opening 42 is formed so as to move into the rear supply passage 40. The outer inflow range 46 in the radial direction is limited by the wall extending almost in parallel with a rotational axis of the impeller 14 against the rear supply passage 40. Therefore, the formation of voltex flow generating fuel reverse flow toward the opening suction 42 is inhibited by the inflow range 46 or the overflowing range, thus it is possible to make fuel flow from the suction opening 42 smoothly into the rear supply passage 40.