A device for ventilating a side window of a motor vehicle, especially an automobile, has an air guide channel that is located in a vehicle door or other side component that contains the side window near a lower area of the side window. Air outlets of the guide channel are directed at the side window and are located in an area that faces the inside window. The ventilating device is made, especially in areas visible to vehicle occupants, in a suitable visual design. The air guide channel is formed in a separate channel part that is mounted on the vehicle side component and which contains air outlets that terminate in the vicinity of a gap formed between the vehicle side component and the side window.