To provide a fuel injection device strengthening a vortex flow (a tumble flow, a swirl flow) in a cylinder while avoiding cylinder wet.

An air blast injector includes: a first injector 21 injecting fuel; a second injector 22 injecting pressurized air; and an injection hole forming member formed with a fuel injection hole 4 injecting air-mixed fuel into the cylinder and an air injection hole 5 injecting only the pressurized air into the cylinder. The air-mixed fuel is injected from the fuel injection hole 4 toward the upper side of the cylinder 6 as shown by an arrow C in order to strengthen the tumble flow. The pressurized air is injected from the air injection hole 5 to a side higher than the injection direction of the fuel injection hole 4 as shown by an arrow B so that the pressurized air is injected in a direction strengthening the tumble flow and toward the peripheral side of the tumble flow. Thereby, an air curtain is formed on the periphery of the tumble flow, and the tumble flow is strengthened while avoiding the cylinder wet.