An apparatus for injecting fuel into the combustion chamber of an internal combustion engine, having an injection nozzle and following the injection nozzle a partition (12, 23, 29) which is provided with through openings (13) for the injection streams and is embodied as a guide device for a partial flow of combustion air, which flow is accelerated by the injector action of the fuel streams in the through openings (13). A device (26, 24, 32) for preheating the partial flow of combustion air is also secured to the partition (12, 23, 29). In this apparatus, the partial flow of combustion air circulates virtually continuously through the partition (12, 23, 29) embodied as a guide device, and the acceleration caused by the injector action of the fuel streams increases with increasing engine rpm. This has the advantage that over the entire power and rpm range of the engine, a uniform course of combustion and a reduction of toxic emissions is attainable.