Fuel pump

The present invention provides a fuel pump capable of suppressing sticking of a plunger. The fuel pump of the present invention includes a plunger 2 that reciprocates, a cylinder 6 in which a guide hole 6a that guides the reciprocating motion of the plunger 2 extends in the axial direction, and a pump body 1 that holds the cylinder 6. The pump body 1 includes a cylinder insertion hole 1g into which the cylinder 6 is inserted, and a pressurizing chamber 11 that communicates with the cylinder insertion hole 1g and has a volume increased or decreased by the reciprocating motion of the plunger 2. The cylinder 6 includes a press-fitting portion 6b press-fitted into the inner peripheral surface of the cylinder insertion hole 1g, and a groove 6d formed at a position corresponding to the press-fitting portion 6b on the inner peripheral surface of the guide hole 6a.