To obtain uniform fuel splay having a good atomization characteristic from an injection beginning to an injection end and to supply fuel and compressed air by surely injecting them from a nozzle port.

A fuel passage for guiding fuel from an fuel valve A to a nozzle 26 comprises a fuel guiding passage 27b arranged inside a needle 27 for guiding the fuel to an intermediate part of the needle 27, and a fuel guiding passage 27c which is arranged obliquely to the nozzle port direction from a tip of the fuel guiding passage 27b and which opens to an outer periphery of the intermediate part of the needle 27 for guiding the fuel to the outer periphery of the intermediate part of the needle 27. An air passage for guiding compressed air into a nozzle 26 comprises an air guiding passage 26c which opens to the outer periphery of the intermediate part of the needle 27 for guiding the compressed air to the outer periphery of the intermediate part of the needle 27. When a needle valve B opens, the fuel and the compressed air are combined and mixed with each other in the outer periphery of the intermediate part of the needle 27, whereby they are guided to the nozzle port.