An apparatus for gasifying pulverized coal, the apparatus comprising a housing with a granulated slag discharge opening in a bottom of the housing, and a producer gas outlet opening in a lower part of the housing; a layer of thermal insulation lining the housing; a pulverized coal burner having a discharge area in the top of the housing; a layer of heat-resistant lining located above the producer gas outlet opening; a steam injection inlet; and a plurality of ducts arranged between the heat-resistant lining and the thermal insulation and extending between the steam injection inlet to the discharge area, each of the ducts having an outlet opening arranged at a level of the discharge area and an inlet opening arranged above the steam injection means. Steam is injected into the housing and the producer gas is cooled with a plurality of cooling medium supply nozzles arranged in the housing.