In a glow plug, in particular for diesel engines, with a body and an ignition tube (13) which is attached therein and closed at its tip and in which a heating resistor (1) and a control resistor (2) which is connected electrically thereto in series and has a positive temperature coefficient are mounted, a material (4) with a heat capacity which delays the heating up of the control resistor by the heating resistor is provided in order to shorten the heating-up time without unacceptably high switch-on current peak between heating resistor (1) and control resistor (2). <IMAGE>
