Abstract: The invention relates to an air conditioner for cooling electrical parts which are situated in a cabinet. A coolant circulation consisting of evaporator, condenser and compressor is provided. The air heated by the electrical parts is blown past the evaporator inside a housing and is returned into the cabinet to be cooled. A condenser is provided for heat dissipation. The housing of the air conditioner is subdivided into a first area and into a second area by a wall, whereby the wall seals the respective air streams from one another. All components sensitive to dirt, dust, etc. are accommodated in the first area, whereas the condenser and an aerator are situated in the second area.