This fuel pump is provided with: an outer gear; an inner gear; a housing that houses both the gears; a rotary shaft (3a) driven to rotate by an electric motor; and a cylindrical sliding bearing (50) that radially bears the rotary shaft (3a) from the outer circumferential side, and radially bears the inner gear from the inner circumferential side. The fuel pump suctions/discharges fuel as a resultof both the gears rotating in response to the rotary shaft (3a) while increasing/decreasing the volume of a gear chamber (40). A casing (80) of the housing has a shaft bearing surface (82) through which the sliding bearing (50) penetrates and which bears the inner gear (20) in a shaft direction (Da) from the side of the motor. The sliding bearing (50) has: an inner circumferential side step section (52) formed into a stepped shape by increasing the inner diameter (Di) on the opposite side of the motor in the shaft direction (Da); and an outer circumferential side step section (56) formed intoa stepped shape by increasing the outer diameter (Do) of the side of the motor in the shaft direction (Da) more than on the shaft bearing surface (82).