lower portions of the moving beds of the respective stages the flowing moving speed of the desulfurizing and dedusting material of the respective stages may be adjusted in such a way as the flowing speed at the forward stage may be faster two layers stages of moving beds have been explained in connection with fig5 the number of the moving beds however must not necessarily be limited to two layers but may be one or more than three the gas having the following composition was prepared as the testing gas assuming the coal gasification gas and treated by the apparatus as shown in fig1 ______________________________________h sub 2 15 volumetric co 15 volumetric co sub 2 10 volumetric h sub 2 o 10 volumetric h sub 2 s 1500 ppmdust 3 g nm sup 3______________________________________ the desulfurizing temperature in the second moving bed was 500 u00b0 c and crushed iron having a grain sized of 1 0 1 41 mm was used as the dedusting material the desulfurizing and dedusting material was regenerated by being oxidized by 50 air dilution at the temperature of 500 u00b0 c 8 weight percent of the desulfurizing and dedusting material which was recirculated through the first moving bed was extracted and supplied to the second moving bed the material balance of the gas and the desulfurizing and dedusting material were as shown in table 1 and table 2 the concentration of the hydrogen sulfide in the gas outgoing from the outlet of the second moving bed was found to be lowered down to 100 ppm on the other hand the dust content in the gas at the outlet of the second moving bed was reduced to 3 mg nm.