[Object] To perform a magnetic decomposition treatment by effectively utilizing smoke emissions.[Solution Means] When an opening 112 is opened and hot air is blown by a hot air gun 40, the waste is thermally decomposed inside the thermal decomposition treatment chamber 110. When smoke emissions generated by the thermal decomposition pass through a shower 210 and a swashplate filter 220 of the filter section 200, a temperature thereof is lowered and tar is removed, and then the smoke emissions pass: through a blower 230, and when the smoke emissions pass through a water tank filter 240, tar is further removed, and moisture is removed by a cloth filter 250. Thereafter, odor is eliminated by a zeolite filter 260 and an activated carbon filter 270, and then, from an intake duct 30, and the smoke emissions are fed to the thermal decomposition treatment chamber 110.No new matter was added in the amendment.