To provide a pollutant treatment method good in economical efficiency capable of easily and certainly removing a toxic substance from a pollutant such as polluted soil, industrial waste, incineration ash or fly ash containing an evaporable toxic substance such as dioxins, mercury or PCB to detoxify the pollutant.

A pollutant containing a toxic substance is introduced into the treatment chamber 12 of a vacuum treatment apparatus 16 equipped with a heating means 14 and heated under vacuum to evaporate the toxic substance from the pollutant and a collection/decomposition device 22 is disposed on the vacuum suction passage 18 sucking the atmosphere in the treatment chamber 12 of the vacuum treatment apparatus 16 to collect or decompose the toxic substance sucked from the treatment chamber 12.