Abstract: A furnace for thermal processing of lump solid fuel, comprising a body accommodating a semicoking zone, zones for gasifying semicoke and for cooling waste solid material and chambers adapted for feeding gas into said zones and discharging a vapor-gas mixture therefrom, said zones and chambers being arranged in succession along the height of the furnace body. The furnace is furnished with an unloading device for discharging solid waste material, said device being located in the bottom part of the furnace body and constituting a hopper with a water seal having a cylindrical bottom passing into a sloping trough. Mounted above the cylindrical portion of the bottom is a sector rocking-type pusher and above the sloping trough - a mechanical shovel associated with the sector pusher in such a manner that a working stroke of the sector pusher corresponds to an idle stroke of the mechanical shovel.