To provide a fuel injection valve wherein a fuel supply amount can be high accurately set without limitation in work accuracy.

A fixed rod 12 having a fuel passage 13a in the inside is sheathed by an injection nozzle 14 so as to form an air chamber 13 in the outside, in the air chamber 13, a movable cylinder member 15 moved in an axial direction is stored, by one way movement in the axial direction, an injection valve element 16 integrally formed with the movable cylinder member 15 is constituted so as to open an injection port, also the movable cylinder member 15 is engaged with a fuel valve means 17 opening/closing the fuel passage 13a in the halfway performing movement opening the injection port, the fuel valve means 17 is opened. Engagement timing is measured by a distance S1 between the injection valve element 16 intensively arranged in an injection port side and the fuel valve means 17.