NOVELTY - The apparatus includes an extruder (9) with reaction tube (3) through which waste plastic raw material is supplied to heater (10) positioned at the outer wall of exhaust outlet (2) of extruder. The thermolysis tank (13) for thermolysis of polyvinyl chloride in melt, is connected with exhaust outlet. The discharge apparatus (19) and an aspirator (16) for suction removal of hydrogen chloride are provided.    DETAILED DESCRIPTION - The apparatus includes an extruder with reaction tube. The waste plastic containing polyvinyl chloride is supplied through insertion opening (1) at one end of reaction tube. The reaction tube has exhaust outlet at the other end. The heater is attached at the outer wall of the exhaust outlet which does not carry out thermolysis. The thermolysis tank to carry out thermolysis of polyvinyl chloride in the melt is provided. The exhaust outlet of the extruder and the upper part of the thermolysis tank are connected through elimination guide pipe (11). The pipe has material sealant (11a) by which melt is formed. An aspirator for suction removal of hydrogen chloride formed during thermolysis in the tank and discharge apparatus for melt, at the bottom of tank are provided.    USE -   For melting and thermolysis of plastic waste material.    ADVANTAGE -   The hydrogen chloride (HCl) formed during thermolysis is removed forcedly. Even when granulation of lump of recovered solid component occurs, the corrosion of furnace interior does not occur. The reverse flow of generated HCl from the tank to the extruder does not arise. Hence corrosion of extruder is prevented. The desalinating efficiency is increased. The entire process is carried out in short time.    DESCRIPTION OF DRAWING(S) - The figure shows the plastic melting and thermolysis apparatus. (1) Insertion opening; (2) Exhaust outlet; (3) Reaction tube; (9) Extruder; (10) Heater; (11) Elimination guide pipe; (11a) Material sealant; (13) Thermolysis tank; (16) Aspirator; (19) Discharge apparatus.