PURPOSE: To possibly set change pressure that changes the ratio of opening pressure of an injection nozzle to flow rate from low ratio to high ratio by defining a first and a second paths in a flow control means, having a valve member that closes the second passage while the upstream pressure is below a preset value.

CONSTITUTION: A flow control means 14 has a first path 32 that has a control part 33 and a second path 34 that is obstructed only by a control valve assembly 36, the assembly 36 obstructs flow of the path 34 at low pressure. As for the control part 33 and the opening pressure of the assembly 36 (as a change pressure as below), while the engine is in idle operation and the pressure in the path 34 is lower than the opening pressure of the assembly 36, the fuel is supplied at a low rate only through the path 32 to show a good low rate combustion characters. While the engine is at a high speed, fuel pressure in the path 34 becomes higher than the change pressure of the assembly 36, so the fuel flows through both path 32 and 34. Under this condition, the fuel flow is controlled by a spray orifice of nozzle in a normal state.