The air conditioning device for electronic components features three channels (6, 7, 8) for two flowing fluids that are in heat exchange with one another. In the first operating mode these two fluids are guided by means of switchable flaps into two selected channels (7, 8) where they are in heat exchange with one another at a partition (12) that is equipped with heat exchange elements (12, 13). In a second operating mode the flaps are switched in such a manner that the two fluids are in heat exchange with one another at a Peltier element (9) that is equipped on both sides with heat exchange elements (9, 11). In a third operating mode the Peltier element is switched as a heating element. In the first operating mode on the other hand the Peltier element is deactivated and consumes no electric energy.