PURPOSE: To easily adjust the stroke of a plunger by arranging each adjusting member having a desired thickness for adjusting an interval between a housing and a second member, or an interval between the first member and a second member, either in an interval housing and between the second member or in an interval between the first/second members or in both terminals.

CONSTITUTION: A main body 12 is made up of a nozzle head 16 which is a first member coaxially attached to one end side of a tubular housing 14 and a fuel introducing pipe 18 which is a second member coaxially attached to the other side of the housing 14. A plane washer 60 is arranged between the housing 14 and the nozzle head 16 or between the housing and the fuel introducing pipe 18 as an adjusting member. Namely, length between the back end surface 56 of the nozzle head 16 and the front end surface of a buffering material 58 is enlarged only by the plate thickness of the plane washer 60. Hereby, the stroke of a plunger 44 can be easily adjusted so that injection characteristics can be stabilized.