FUEL PUMP

Provided is a fuel pump capable of improving volumetric efficiency. The fuel pump of the present invention includes: a pump body 1 in which a pressurizing chamber 11 is formed; a plunger 2 that reciprocates in the pressurizing chamber 11; a discharge valve mechanism 8 that discharges fuel in the pressurizing chamber 11 to a discharge chamber 87; and a relief valve mechanism 4. The relief valve mechanism 4 opens when a difference between a pressure of the fuel in the discharge chamber 87 and a pressure of the fuel in the pressurizing chamber 11 exceeds a set value, and returns the fuel in the discharge chamber 87 to the pressurizing chamber 11. As viewed from a first direction along which the plunger 2 reciprocates, the discharge valve mechanism 8 and the relief valve mechanism 4 are disposed in a direction where the moving directions of the respective valve elements 82, 43 intersect with each other. The relief valve mechanism 4 is disposed at a position that overlaps with the pressurizing chamber 11 in the first direction and in a second direction that is a moving direction of the valve element 43 of the relief valve mechanism 4.