Abstract: Vaporizing and concentration drying apparatus and method are disclosed. The apparatus and method prepare good quality of condensed water and save evaporation energy and are wide used in making contaminated waste water become distilled water and in purification of the waste water and in concentration and drying of varieties of environmental polluting sludge. The apparatus and method recover and reuse the heating energy, which energy was applied to the vapor so as to heat the vapor to a high temperature and to remove the environmental polluting impurities, such as odor, B.O.D. and C.O.D. laden in the vapor, so that the apparatus and method remarkably save the cost for the heating energy. The apparatus saves the energy by 2-10 times in comparison with the conventional apparatus.