To incinerate a large amount of polymer waste at one time by a method wherein the polymer waste being fed in a primary incineration furance is incinerated by hot air, and the exhaust gas is burnt in a secondary incineration furnace by burner flames and high temperature air, and hydrogen chloride and solid content are removed by a neutralizing solution, and the solid content is fed to the primary incineration furnace.

By opening/closing an opening/closing lid 7 and a fireproof door 8 in order, polymer waste is fed into a primary incineration furnace 2 being operated by hot air, from a hot air jetting nozzle. The pressure in the primary incineration furnace 2 is kept at a specified vale by a damper, and the exhaust gas is secondarily incinerated in a secondary incineration furnace 3 in which a main burner 17 and a hot air nozzle 18 are arranged. The exhaust gas which is completely burnt here is washed and cooled by a washing solution in which a neutralizing agent is mixed, in a gas cooling chamber 26, and hydrogen chloride in the exhaust gas is removed. For the exhaust gas being cooled here, hydrochloric acid, and also, solid content are separated and removed by a washing solution in a sedimentation/ separation tank 27, and the exhaust gas is discharged into the atmosphere. The solid content deposited on the bottom of the sedimentation/separation tank 27 is condensed in a sludge condensation tank 52, and after drying on the bottom of the primary incineration furnace 2, the solid content is incinerated.