Abstract: A device for preheating fuel for an ultrasonic atomizer (11) is shown, in which the fuel for an engine-independent heater operated with liquid fuel is atomized. The heating element (20), which preferably consists of a PTC element, is arranged in physical proximity to the ultrasonic atomizer (11) and outside the fuel feed line (17) so that it is switched off as soon as a sufficient amount of heat is generated by the combustion chamber (3), so that the fuel is adequately atomized on the atomizer plate. Reliable possibility of start at low temperatures (down to cA. -40.degree. C.) is thus achieved at low power consumption in the start-up range.