To improve pump efficiency of a fuel pump.

An impeller rotating in a pump casing is approximately disk- shaped. In an area extending along the outer peripheries of two sides, groups of recess parts are formed repeatedly and mutually spaced at certain intervals in the circumferential direction. A partition wall is secured between adjoining recess parts. The inner end part and the outer end part of the partition wall in the radial direction are on the same radius. The intermediate part of the partition wall in the radial direction is bent backward in the rotational direction of the impeller. The fuel pump is capable of obtaining high pump efficiency by suppressing the rate of occurrence of break away or vortex in a flow of fuel. Preferably, maximum bend is 0.1-1.0 mm, the shape of a bend of the front side of the rotational direction on two sides of the partition wall is a circular arc with a radius of 2.3-4.3 mm, and/or the shape of a bend on the back side of the rotational direction is a circular arc with a radius of 3.0-5.0 mm.