Abstract: An air preheating device for diesel internal combustion engines, includes a fuel atomizer (2) and an ignition device arranged in the air intake pipe (1). In order to achieve reliable ignition and sufficient preheating of induction air having pulsating currents, an ultrasonic atomizer is used and its atomized stream (3) is located in a zone (5) of stabilized air flow in the intake pipe. The ignition device (4) is also positioned in the zone (5) of stabilized flow and ignites the atomized stream (3). The ultrasonic element (13) is cooled by being positioned in a cool partial current of the intake air.