To suppress the inclination of an impeller while increasing pump capacity.

This fuel pump 10 comprises an impeller of generally disk shape and a casing for rotatably storing the impeller. A plurality of groove groups concentrically disposed around the center axis thereof are formed in at least one face of the impeller. A plurality of independent grooves 24a, 24b, 24c extending from the upstream end to the downstream end are formed in the inner surface of the casing facing the surface of the impeller in which the groove groups are formed. A fuel is sucked from the outside of the casing to those places 27a, 27b, 27c near the upstream side end of the grooves 24a, 24b, 24c, and the sucked fuel is discharged to the outside of the casing from those places 29a, 29b, 29c near the downstream side end of the grooves 24a, 24b, 24c. The grooves 24a, 24b, 24c face at least two or more groove groups among the plurality of groove groups formed in the impeller.