of the fuel supply of predetermined quantity by the use of the preset device 48 will now be described first before performing the fuel supplying operation a push button key 49 of the preset device 48 which shows the desired fuel supplying quantity is pushed to establish the desired fuel supplying quantity in the control part 47 this fuel supplying quantity is transmitted to the control part 47 and memorized therein when the establishing of the fuel supplying quantity by the preset device 48 is completed the fuel supplying nozzle 15 is inserted inside the fuel intake opening 16a of the vehicle 16 and the supply of fuel is started by pulling the nozzle lever 22 by the insertion of the fuel supplying nozzle 15 the solenoid valve actuates and opens as described above accordingly the pressure inside the diaphragm chamber 36 does not become of negative pressure upon starting of the fuel supply by pulling the nozzle lever 22 and thus introduces no inconveniences in this embodiment of the invention it is organized so that the solenoid valve actuates and opens by the insertion of the fuel supplying nozzle 15 and therefore when the nozzle lever 22 is pulled by mistake before the fuel supplying nozzle 15 is inserted inside the fuel intake opening 16a the valve 23 is closed instantly by the operation of the automatic valve closing mechanism hence preventing an accident in which the fuel is sprayed around when the fuel supplying quantity reaches the predetermined fuel supplying quantity as the fuel supplying procedure progresses the solenoid valve 41 is cut off from its actuating state by the signal from the control part 47 and.