NOVELTY - The microorganisms acclimatization apparatus contains waste-water treatment tank (1), cooling unit and sludge circulation unit. The apparatus makes high temperature waste-water (A) acclimatize microorganisms which are used to aerobically decompose organic matter in high temperature waste-water. The cooling unit cools the high temperature waste-water. The sludge circulation unit circulates the sludge containing microorganisms between high temperature waste-water portion and medium-temperature waste-water portion.    USE - Microorganisms acclimatization apparatus for decomposing organic material in waste-water from sewage, human waste, food-processing factory and chemical industry.    ADVANTAGE - The microorganisms acclimatization apparatus processes hot organic waste-water economically, efficiently and stably without requiring change in installation and processing activity.    DETAILED DESCRIPTION - The microorganism acclimatization apparatus contains waste-water treatment tank, cooling unit and sludge circulation unit. The apparatus makes high temperature waste-water acclimatize microorganisms which are used to aerobically decompose organic matter in high temperature waste-water. The waste-water treatment tank has inlet at an end and discharge at other end for high temperature waste-water. The cooling unit cools the high temperature waste-water, and forms high temperature waste-water portion and medium-temperature waste-water portion along flow direction of waste-water in treatment tank. The sludge circulation unit circulates the sludge containing microorganisms between high temperature waste-water portion and medium-temperature waste-water portion. INDEPENDENT CLAIMS are included for the following:    (1) waste-water treatment equipment;    (2) waste-water treatment method; and    (3) microorganisms acclimatization method.    DESCRIPTION OF DRAWING(S) - The drawings show microorganisms acclimatization apparatus and waste water equipment and surface view of acclimatization apparatus.    Waste-water treatment tank (1)    Waste-water inlet tube (3)    Treated-water discharge pipe (5)    Waste-water (A)    Treated water (C)