A method of supplying scents to a room of a motor-car. In this method, a scent holder is provided within the room of the motor vehicle, the scent holder containing scents bearing materials for emitting different scents useful for a driver of the motor vehicle. Reference data for respective driving conditions of the motor vehicle are stored, the reference data indicating need for supply of respective scents. After storing the reference data, a driving condition of the motor vehicle is detected for producing an electric drive signal representing the driving condition. The drive signal thus produced is compared with a corresponding reference datum for determining whether or not the detected driving condition requires one of the scents contained in the scent holder. When the detected driving condition requires the one scent, one scent bearing material containing the one scent is selected. Then, the one scent from the one scent bearing material is supplied to the room of the motor vehicle.