To eliminate a sliding failure of each of a command piston 1 and a nozzle needle 2 at one collective position by rotating the command piston 1 and the nozzle needle 2.

In the sliding surface of a sliding part 51 of the command piston 1 of a fuel injection nozzle, a spiral groove 53 is provided for giving rotation to the command piston 1 around the center axis of the command piston 1 with the overflow of fuel from the side of a control chamber via a clearance 52 to the side of a spring chamber. In the sliding surface of a sliding part 61 of the nozzle needle 2 of the fuel injection nozzle, a spiral groove 63 is provided for giving rotation to the nozzle needle 2 around the center axis of the nozzle needle 2 with the overflow of fuel from the side of a fuel sump chamber via a clearance 62 to the side of the spring chamber. Thus, local wear can be reduced at a sliding portion between the command piston 1 and a lower body 5 and at a sliding portion between the nozzle needle 2 and a nozzle body 6.