To improve fuel spraying characteristics by changing a fuel particle diameter atomized in accordance with operating conditions.

A fuel spraying route is formed of a plurality of second jet holes 7b formed in a fixed jet hole plate 7 and of a plurality of jet holes 6c formed in a movable jet hole plate 6 so as to be movable in a radial direction. The movable jet hole plate 6 is moved in the radial direction by a spring member 8 so as to move the jet holes 6c to the second jet holes 7b, positions of the jet holes 6c to the second jet holes 7b are varied so as to vary and control the sectional area of the fuel spraying route, and the particle diameter of fuel to be sprayed is varied and controlled.