Vane pieces (31) which are in an outer peripheral edge portion of an impeller (30) are divided into front and rear groups by a partition wall (32), and arranged in a staggered pattern, and outer peripheral faces of the vane pieces (31) are protruded toward the outer peripheral side with respect to the outer peripheral face of the partition wall (32). Therefore, fuel portions respectively entering vane grooves (33) which are divided into front and rear groups do not simultaneously collide against end faces (9b) of radial seal portions (9a). Consequently, the level of noises due to the fuel collision can be lowered.
Furthermore, a reverse-flow region is prevented from being produced immediately above the partition wall (32). Therefore, the pump efficiency can be improved.