Abstract: To provide a fuel injection nozzle that not only enables adjustment of a flow rate, but also causes contaminants and gum to pass through to reduce an effect on the flow rate. A fuel injection nozzle having a flat portion on an outer peripheral face of a needle is disclosed. The fuel injection nozzle opens at a predetermined angle, and, by the needle moving in an axial direction in an inner periphery of an injection hole, gaps are formed between the outer peripheral face of the needle and an inner peripheral face of the injection hole of a nozzle body. Adjustment to a desired fuel injection flow rate is possible by setting an outer diameter of the needle, a distance from the seat portion to a starting position of the flat portion on the outer peripheral face of the needle, and an incline angle of the flat portion.