A vapor lock in a fuel pump can be prevented by reducing the formation of vapor within the fuel. A first group of concavities may be formed in an inner circumferential region of an intake side face of an impeller, and a second group of concavities may be formed concentrically in a region outside of the first group of concavities. A third group of concavities that communicates with the second group of concavities may be formed in a discharge side face of the impeller. The impeller is housed within a casing. A first groove that faces the first group of concavities and a second groove that faces the second group of concavities may be formed in the face of the casing that faces the intake side face of the impeller. A third groove that faces the third group of concavities may be formed in the face of the casing that faces the discharge side face of the impeller.