PURPOSE: To improve responsiveness at the time of opening and closing of a solenoid spill valve to control flowing of fuel in a fuel supply passage of a diesel engine.

CONSTITUTION: A needle valve 24 to pass through or to block a spill passage 18 consisting of an inlet passage 14 to be supplied with high force feeding pressure and an outlet passage communicated to a low pressure chamber is provided. A valve spring 26 to generate upward energizing force is arranged on the lower end of the needle valve 24. A solenoid 28 to apply downward electromagnetic attracting force is provided on the needle valve 24. A communicating passage 22 to open to the outlet passage 16 and a pressure chamber 20 is provided. A hydraulic pressure introducing passage 30 to communicate the communicating passage 22 to an upper part space of an armature part 24b only in a territory where opening of the needle valve 24 exceeds specified opening is provided.