A novel fluorination procedure of etheric substrates adsorbed on porous aluminium fluoride (PAF) using gaseous fluorine has been investigated. The reaction of ethyl 1,1,2,2-tetrafluoroethylether 1 and 2-chloro-1,1,2-trifluoroethylmethylether 9 with fluorine proceeds with upto 58% selectivity for α-monofluorinated 1 and 96% selectivity for α-monofluorinated 9. At the same time, charring can be avoided