PURPOSE: To improve firing property in start in a fuel supply device for an internal combustion engine using low quality fuel by forming compressed gas flow around a liquid fuel flowing port of a fuel flowing nozzle to promote the atomization of fuel.

CONSTITUTION: A fuel injection nozzle 32 of an internal combustion engine 11 consists of a hosing 33, a compressed air supply pipe 34 and a liquid fuel supply pipe 35. Said pipe 35 is formed on the end with a liquid fuel flowing port 37. And between an opening end of the housing 33 and the end of said 35 is formed a compressed gas discharging port 38. Before starting the engine 11 is actuated a pump 47 to fill air in a compressed gas tank 43. Then, when a starter is operated, a switch valves 41, 45 are opened and compressed air is sent from a tank 43 to said pipe 34 of the nozzle 32 and discharged from said port 38 toward a scavenging path 27. Thus, the fuel flowing port 37 has negative presssure so that fuel is sucked from an auxiliary cabureter 29, mixed with air and atomized to explode in a combustion chamber 23.