PURPOSE: To enable optimum pilot injection to be effected in accordance with the state of operation, by performing pilot injection and main injection by one opening and closing operation of a solenoid valve during a single injection period, and controlling the time of the change-over of the valve in accordance with the state of operation of an engine.

CONSTITUTION: When the fuel pressure fed to a high pressure port 48 of valve means 47 arranged in a fuel passage 33 between a solenoid valve 44 and a nozzle 37 becomes equal to the pressure in an open valve chamber of the nozzle 37, a port 48 is opened to allow the fuel to flow into a front chamber. Part thereof is returned from an escape hole via a rear chamber and a return port 51 to a tank 50, and the pressure in the front chamber is lowered in proportion to the restriction by an orifice. As the pressure in the front chamber acts on the front of a valve body 53, the valve body is retracted with the lowering of the pressure, and the port 51 is closed. Accordingly, after the rise of the fuel pressure from the pressure chamber 34 to the open valve pressure of a nozzle 37, it is lowered to the close valve pressure once, then it is increased to the open valve pressure again, and pilot injection and main injection are carried out in one compression stroke. Further, a control circuit 43 is provided for setting the time for change over valve means 47 in accordance with the state of operation of an engine.