NOVELTY - The waste plastic processing apparatus (40) has the thermolysis apparatus (10) which includes a cylinder (13) arranged rotatably inside the cylinder (11) which is heated to predetermined temperature longitudinally. Waste plastic insertion opening and discharge port (13d) are provided at respective ends of the cylinder (13).    USE - For dechlorination process of harmful chlorine contained in waste plastic.    ADVANTAGE - As the outer cylinder is heated longitudinally to predetermined temperature, thermolysis of the charged waste plastic is started at low temperature. Thermolysis is advanced by transferring the waste plastic from low temperature area to high temperature area with the rotation of the inner cylinder. Fluidity of the melting plastics increases and the thermolysis process efficiency is also increased. As overheating is prevented effectively, good cracked distillate is obtained.    DETAILED DESCRIPTION - The temperature of the outer cylinder at one end is relatively low and the other end is relatively high. The outer cylinder has gas passageways through which gas of predetermined temperature is passed. Ceramic balls and baffle plates are provided inside the cylinder (13). Another thermolysis apparatus is connected to the thermolysis apparatus (10) through melting plastic discharge pipe. In the processing apparatus with one thermolysis apparatus, one end of the outer cylinder (11) is heated by 300-350degreesC and the other end is heated by 500-550degreesC. In the processing apparatus with two interconnected thermolysis units, the one end of first outer cylinder is heated by 100-200degreesC and the other end is heated by 300-350degreesC and an end of the second outer cylinder is heated by 400-450degreesC and the other end by 500-550degreesC.    DESCRIPTION OF DRAWING(S) - The figure shows the outline structure of the waste plastic processing apparatus.    Thermolysis apparatus (10)    Cylinders (11,13)    Discharge port (13d)    Waste plastic processing apparatus (40)