PROBLEM TO BE SOLVED: To provide a method and apparatus for processing soil and sand that can prevent failures having effect on the ecosystem in the site using this soil and sand due to organisms mixed in the soil and sand used as construction materials.SOLUTION: Boiler piping 3 connected to a boiler 2 is buried in soil and sand S, the surface of the soil and sand S is brought into a state of being covered with a heat retaining member 4, heating steam W is supplied to the boiler piping 3 from the boiler 2, and the heating steam W is injected to the soil and sand S from a nozzle 3a. Thereby the soil and sand S are heated larger than a preset predetermined temperature, a state of being heated at the predetermined temperature or more is maintained for a preset predetermined time or more, and the protein of organisms X mixed in the soil and sand S is varied irreversibly.SELECTED DRAWING: Figure 1
