To provide a fuel injection nozzle capable of gradually increasing the effective cross-sectional area of a nozzle port according to a lift quantity of a needle valve, being easy in manufacture, improving exhaust emission and having a stable injection characteristic by properly arranging a fuel passage, a seat part and the nozzle port.

The central fuel passage 19 reaching up to the tip part is formed in a central shaft part of the needle valve 5 by paying attention to forming the central fuel passage 19 in a central part of the needle valve 5 and gradually opening the nozzle port 11 according to a lift of the needle valve 5. The needle valve 5 is seated on a seat surface 23 of a nozzle body 3 so as to be positioned in the tip part to form a seat part 25 capable of cutting off the central fuel passage 19. When the needle valve 5 lifts from the seat surface, the nozzle port 11 can be opened.