An electric heating device as supplemental heating for motor vehicles includes as the heating elements power transistors directly mounted on the printed circuit board. For efficient removal of the dissipation heat from the power transistors the latter are in direct contact on their underside with a cooling element via openings in the printed circuit board. In order to simplify manufacture, the cooling elements are formed in two pieces: the heat conducting disk with a small thermal mass insertable into the opening of the printed circuit board, and the cooling body which can be connected to that heat-conducting element.