Method for filling a tank with pressurized hydrogen via a filling station comprising at least one buffer container and a fluid circuit connected to said at least one buffer container, the circuit of the filling station comprising a first end connected to at least one source of hydrogen gas, the circuit comprising a second end fitted with a transfer pipe intended to be connected removably to the tank that is to be filled, the method involving a step of purifying the hydrogen supplied by the source in a purification member before transferring same to the at least one buffer container, the circuit of the filling station further comprising at least one compression member for compressing the pressurized gas in order to fill the at least one buffer container, the method being characterized in that it comprises a step of transferring heat energy between, on the one hand, the compressed gas of the outlet from the compression member and, on the other hand, the purification member.