To provide a fuel injection device capable of properly removing a foreign substance adhered to a fuel filter in a fuel tank, and preventing the intrusion of the foreign substance on a pressure regulator side.

The fuel injection device includes: a plunger pump 1 sucking fuel stored in the fuel tank 2 and supplying the fuel to a fuel injection valve; a pressure regulator 25 adjusting the fuel supplied from the plunger pump 1 to a predetermined pressure; return piping 34 returning the fuel from the pressure regulator 25 to the fuel tank 2; and a return jet nozzle 36 disposed inside the fuel tank 2 and jetting the returned fuel fed from the return piping 34 toward the fuel filter 8 in the fuel tank 2.