Fastening device for fastening an electronic device in a vehicle

The fastening device (1) has a receiving device (8) that is provided for receiving the electronic device. The receiving device is pivotally mounted at end (4) of support arm (2). The end (6) of support arm is connected to vehicle. The support arm is provided with an inner space which is accessed from outside through a longitudinal slot (3). The longitudinal slot is extended over more than half of length of the support arm.