the processed soil without the use of chemical agents to be able to be sterilized and it is excellent in safety, and to provide a soil sterilizing device capable of sterilizing the treatment target soil efficiently and sufficiently. And the boiler (2) for generating steam, the superheated steam generator that generates superheated steam from the steam is transferred from the boiler (3), embedded in the soil (X) to be processed during the sterilization process, the soil ( superheated steam supply unit for supplying the superheated steam into X) and (4), the supply tube supplying the superheated steam supply unit superheated steam generated in the superheated steam generator (3) (4) and (5) , to have a structure equipped with a.化学薬剤を使用することなく処理対象土壌を殺菌処理することができて安全性に優れると共に、処理対象土壌を効率良くかつ十分に殺菌できる土壌殺菌処理装置を提供する。水蒸気を生成するボイラー(2)と、前記ボイラーから移送される水蒸気から過熱水蒸気を発生させる過熱水蒸気発生装置(3)と、殺菌処理時に処理対象の土壌(X)内に埋設され、該土壌(X)内に過熱水蒸気を供給する過熱水蒸気供給部(4)と、前記過熱水蒸気発生装置(3)で発生する過熱水蒸気を前記過熱水蒸気供給部(4)に供給する供給管部(5)と、を備えた構成とする。
