Bioremediation technology is outlined. The bioremediation technology is a contamination-remedying technology for the injurious chemical matter discharged in the environment to be made innocuous by utilizing the decomposing ability of microorganisms. That technology is characterized by its energywise economical performance, secondary waste which is not producible and remedy which is possible on site against the contamination. As a treatment system, that technology comprises solid phase bioremediation (The contaminated soil is purified in a soil treatment unit.), slurry phase bioremediation (The contaminated soil is made slurry and decomposed by microorganisms.) and in-situ bioremediation (The treatment is made by injecting nutrients and microorganisms underground.). As for how to use the microorganisms, there are two methods: One in which living groups of microorganisms are activated and the other in which microorganisms are artificially cultivated. As contaminants in the US, listed are organic solvent, wood preservative, high-molecular aromatic halide, agricultural chemical, military waste, heavy metal waste and radioactive waste. 11 refs., 5 figs., 1 tab.