PURPOSE: To inhibit the formation of COS and to improve the recovery rate of sulfur by the reduction of SO2 by a method wherein gas containing SO2 is passed through a reaction zone composed of a mixture of a solid reducing agent such as coal particles and a solid catalyst such as alumina.

CONSTITUTION: A fixed bed or a moving bed consisting of a mixture of 100 pts. wt. of a solid reducing agent such as coal or coke particles and from 5W50pts. wt. of a solid catalyst such as alumina, silica, is prepared. The solid catalyst may be supported on an oxide such as oxide of iron or calcium. Gas containing SO2 kept at a temp of from 700W900°C is passed through a reaction zone consisting of the above fixed bed or moving bed to reduce SO2 to vaporous sulfur. The vaporous sulfur is separated from the effluent of the reaction zone, condensed and recovered.