NOVELTY - Contaminated soil (1) which is to be subjected to aerobic biodegradation process is stored in several containers (21) which are accommodated inside an aerobic treatment chamber (31). The contaminated soil is ventilated by passage of air through the gap which separates the containers, and through holes provided in the containers, and is purified by microorganisms which decompose the contaminants.    USE - For purifying soil contaminated by petroleum type hydrocarbon compounds, halogenated hydrocarbons, dioxins, which is present in the site in which industries and incineration plants are installed, in indoor environments, inside vinyl and glass greenhouses, warehouses and cargo containers.    ADVANTAGE - Enables oxygen to be uniformly supplied to the whole contaminated soil, thus enabling the microbes to purify the soil, efficiently. Prevents scattering of the contaminated soil, and the decomposed material from the soil, as the decomposition process is performed inside the treatment chamber. Hence prevents environmental pollution. Enables temperature, humidity and pH to suitable value to be maintained, and thereby achieving high-degree of purification of the contaminated soil.    DETAILED DESCRIPTION - Contaminated soil (1) which is to be subjected to aerobic biodegradation process is stored in several containers (21) which are accommodated inside an aerobic treatment chamber (31). The contaminated soil is ventilated by passage of air through the gap which separates the containers, and through holes provided in the containers, and is purified by microorganisms which decompose the contaminants. The containers are open, or are provided with a porous lid, and a perforated wall portion. The humidity, temperature, and/or pH, oxygen concentration in each container is monitored, and is maintained at the suitable level at which activity of the microorganisms is maintained. Microorganisms are added to each container, after sterilizing contaminated soil, and after supplying sterilized soil into the container. The depth of the container is set twice the maximum distance at which oxygen reaches the microbes in the container. The contaminated soil is stirred in the container.    An INDEPENDENT CLAIM is included for indoor purifier of contaminated soil.    DESCRIPTION OF DRAWING(S) - The figure shows an explanatory view of the soil purifier.    contaminated soil (1)    containers (21)    treatment chamber (31)    oxygen concentration regulation unit (32)    temperature controller (35)