The invention relates to an electric flight control system for aircraft elevators. The tip ends of bent portions of the mounting legs which have been bent along the back face of the door section are covered with the covering parts which are compatible with material forming the air bag cover so as to be melted and solidified. This way, the user’s sight on the joining process is not necessary. Electrons are deflected or angularly modulated to a second path. An entire portion of the intermediate electrode 18m that is located between the first channel region 14c1 and the second channel region 14c2 overlaps the gate electrode 12 through the intermediate region 14m and the gate insulating film 13. The deviation is used for feedback control so that the displacement driver moves the probe to adjust the distance between the probe and the sample.