PURPOSE: To provide a waste material fuel-combustion plant which has a heat- resistant characteristic and can be used for a long period of time, perform a complete combustion of fuel such as industrial waste material or living waste materials and the like and has no dangerous opportunity to ignite an external stored fuel.

CONSTITUTION: A combustion furnace body (a) is constructed as a water-cooled structure in which a rotary cylinder 3, an air blowing pipe 11 and a fuel supplying mechanism 15 are installed in a combustion chamber 2 provided with a flame guiding passage (c') and an ash discharging mechanism 21 while the water passages are being installed at the cylindrical wall or within the cylindrical wall. Blowers 7 and 13 are connected to the outer ends of the rotary cylinder 3 and the blowing pipe 11 through dampers. The external fuel hopper (b) has a waste material fuel feeding device 23 connected at its upper part, a shielding lid plate 24 is slidably and laterally installed at a lower gate 25 and further an outer end of the fuel supplying mechanism 15 is connected to the bottom part of the external fuel hopper (b).