NOVELTY - Microorganism culture apparatus comprises a tank divided into 3 or more draught chambers, a space is left in the upper part of chambers for passage of air from the bottom, the draught chambers are alternatively filled with a thin layer of humus and granular stones which radiate far infra-red radiations, and an aeration diffuser is arranged in the cylindrical container.    USE - The apparatus is used for biological treatment of waste sludge.    ADVANTAGE - The activity of the soil microbe in the humus is improved by the presence of the infra-red radiating stones. The proliferation of waste putrefying bacteria, such as Salmonella, Staphylococcus aureus, is inhibited. The stones prevent reduction of oxidation-reduction potential (ORP) of sludge water. Stagnation of sludge is prevented and culture of useful bacteria is improved. A soil microbe is effectively dispersed in sludge water and contact of the microbe in humus with sludge water is performed efficiently.    DETAILED DESCRIPTION - Microorganism culture apparatus comprises cultivating and activating microorganisms present in an organic sludge in a rectangular or cylindrical tank (8) divided into 3 or more draught chambers (7) vertically, by level perforated panels (6). A space is left in the upper part of the chambers for passage of air, from the bottom of the tank. The draught chambers are filled with humus (X) in the form of granules, pellets or as a thin layer, and are alternatively filled with granular stones (Y) which radiate a far infra-red radiation, as a thin layer. Air and sludge for treatment, from the bottom of the tank pass through the humus layer towards the upper chambers. An aeration diffuser (9) is arranged in the cylindrical container below the last (lower) perforated panel.    DESCRIPTION OF DRAWING(S) - The figure shows the front elevation cross section of the microorganism culture apparatus.    Culture apparatus (1)    Frame (2)    Legs (3)    Perforated panel (6)    Draught chamber (7)    Cylindrical tank (8)    Aeration diffuser (9)    Humus (X)    Far infra-red radiating stones (graphite silica) (Y)    Pumice stone (Filter medium) (Z)