the present invention relates to a control method for the operation of a fan equipping an electronic device . a determination step detects the vertical or horizontal position of the electronic device . the fan is not started up during the powering up of the device while the device is in a vertical position . the flow of air produced by the “ fireplace ” effect in the device in a vertical position suffices to ensure correct ventilation . according to an improvement the device has a sensor measuring the internal temperature of the device , whatever the position of the device , the fan being started up from a determined temperature . the present invention relates also to a device implementing the method .