Abstract: In a furnace in which the waste is loaded into a central shaft at the bot of which it is held up by a device for letting through small particles after the column of waste has been exposed to degassing and drying heat entering laterally from a smoke chamber. Fresh air is supplied in substoichiometric quantity into the column of waste and is supplied in further quantity through the device for holding up the material in the column as well as just above it and, finally, also in a combustion chamber below the device for afterburning combustible gases. There is an opening between the device for holding up the waste material in the shaft and the inner wall of the shaft to material to form an inclined layer down to the hole at the bottom of the shaft, enclosing a combustion space. An ember bed forms here, from which melted material passes down through a combustion chamber below and through a drain in the floor of the combustion chamber.