PURPOSE: To provide an engine with a vortex chamber capable of decreasing the concentration of flue gas in an engine and improving the fuel consumption.

CONSTITUTION: Air is flow as a vortex flow into a vortex chamber 4 from a main chamber C through a nozzle hole 5, and vortex flow F of air-fuel mixture is produced by performing fuel injection by means of an injector, and then the combustion is completed by injecting ignited air-fuel mixture into a main chamber C from the nozzle hole 5. And an injector with a pencil nozzle 11 longitudinally arranged in the direction perpendicular to the direction of the vortex flow F, and on which a plurality of nozzle holes are formed is provided, and the nozzle holes are so formed as to atomize the atomizing respective different fluxes (a) in the direction perpendicular to the direction of the vortex flow F from the vortex center.