To separate valuable components in each material according to type by heating a waste structure under non-oxidizing conditions in a closed heating furnace to decompose and recover organic materials and thereafter setting plural temperature heightened stages under vacuum in the furnace and condensing and recovering metal components evaporated in each temperature stage.

After a group of waste structures such as waste automobiles are housed in a housing part of a two-stage jig 2 and carried into a heating treatment furnace 1 and the closed furnace 1 is evacuated by a vacuum pump, they are heated by a heating means 4. At this stage, the waste including volatile materials is removed. Next, after gas is introduced by pressure from a non- oxidizing gas storage tank 10, the waste is heated, and gas in a space part 3 is agitated by a fan 9 to decompose organic matter such as plastic. At this time, valves 14, 15 are opened to bring out gas in the furnace to a condenser 8 and to recover liquefied matter 9, and gasified matter is recovered by an adsorber 7. Successively, the waste is furthermore heated by the heating means 4 and the furnace is evacuated by the vacuum pump, allowing zinc and the like to be evaporated and recovered in a condenser 6.