PURPOSE: To minimize a processed high-pressure seal surface so as to obtain sufficient sealing.

CONSTITUTION: Control electromagnet 47-51 and control valves 46, 52-58 are combined in an electromagnetic valve casing 45 to form a structural unit that is inserted as a whole into a pump nozzle casing. The electromagnetic valve casing 45 is fastened between an injection pump 4 and an injection nozzle 6 and has a common end face with the injection pump and injection nozzle respectively. A segment of a high pressure channel 9 running from end face to end face extends in the electromagnetic valve casing 45. A branch channel 19 branched from the high pressure channel segment and leading to a high pressure chamber 54 of a control valve 16 is arranged in the electromagnetic valve casing 45. A low pressure annular groove 66 is arranged between the pump nozzle casing 41 and the electromagnetic valve casing 45. The low pressure annular groove has one side connected to a low pressure channel 21 leading to a low pressure chamber 65 and the other side connected to a communicating bore 67 leading to the outside of the pump nozzle casing 41.