To decompose PCB (polychlorobiphenyls) into salt, water and carbon dioxide while melting PCB-containing oil or PCB-infiltrated, PCB-stuck or PCB-enclosed matter being PCB-containing waste at ultra-high temperature.

PCB-containing waste is disassembled/sorted into a PCB-unimpregnated member and a PCB-impregnated member. The PCB-unimpregnated member is cleaned with an ammonium salt and recycled. The PCB-impregnated member is crushed, which is then supplied to a cyclone furnace 1 together with oil-removed PCB-containing waste and melted/decomposed at ultra-high temperature. The exhaust gas from the cyclone furnace is made to pass through a pyrolysis chamber 2, heat exchangers 3, 5 where a heat source of the exhaust gas is adjusted, an NOx removing reaction chamber 4 where the exhaust gas is treated chemically, a scrubber 6, a multicyclone 7, a bag filter 8 and an adsorption column 9 and discharged to the atmosphere. A water-removed PCB-containing liquid from a water storage part is subjected to solid-liquid separation using an electromagnetic separator 41. PCB in solidified PCB-adsorbed magnetite is desorbed/separated by a regenerated organic solvent such as methanol, distilled and stored in a liquid waste PCB storehouse as recovered PCB.