PURPOSE: To recover methyl bromide contained in air, in high efficiency, by adsorbing the methyl bromide with an activated charcoal which has higher activity at a lower concentration, desorbing the adsorbed methyl bromide by heating under reduced pressure, and then adsorbing with an activated charcoal having higher activity at a higher concentration.

CONSTITUTION: Air in a fumigated space containing 0.6W200mg/l of methyl bromide is treated in the first adsorbing vessel with an activated charcoal (A) which exhibits stronger adsorption activity to methyl bromide at lower concentration region. The first adsorbing vessel is then evacuated to 20W600 Torr with a vacuum pump, and if necessary, introducing an inert gas into the vessel, the activated charcoal (A) is heated at 50W250°C to obtain desorbed methyl bromide at a relatively high concentration. After cooling the desorbed methyl bromide, it is again adsorbed in the second adsorbing vessel with another activated charcoal (B) which exhibits stronger adsorption activity to methyl bromide at higher concentration region. By repeating the procedures, methyl bromide is obtained in high concentration from the activated charcoal (B).