The invention relates to a method for filling a tank with a cryogenic liquid from a storage unit, a filling process during which a part of the cryogenic liquid is transformed into a gas phase in the tank, and in which, during the filling, at least part of the gas thus formed is discharged, characterized in that the method comprises providing a filling station containing a first channel which connects the storage unit to the tank and enables the transfer of cryogenic liquid from the storage unit to the tank, and a second channel which connects a gas outlet of the tank to the filling station and makes it possible to transfer the gases to be discharged from the tank to the filling station, where said gases will be discharged to the outside, the station comprising a means for detecting the presence of cryogenic liquid in the gas transferred to the station, the detection information being transmitted to a unit for acquiring and processing data, inside or outside the station, suitable for automatically stopping the filling apparatus when the tank is considered to be full.