Recently, semiconductor industry has grown rapidly because of the large demand for electronic devices and equipment. The semiconductor industries have also played an important role on the economic growth in Korea. As the environmental regulations become strict, the proper environmental management and the well-developed waste minimization technologies in semiconductor industries are two of urgent problems to be solved. The semiconductor manufacturing process consists of a series of continuous chemical processes, such as cleaning, oxidation, diffusion, photolithography, etching and film deposition. During the processes, various environmentally hazardous wastes are produced. The wastes may be classified as wastewater, gaseous pollutants, and solid wastes. For waste minimization, the substitution of raw materials and process optimization techniques are used, while the selective destruction technologies of toxic chemicals contained in the wastes have been reported. Also, new technologies have been developed for source reduction and waste reduction, such as reduction of toxic chemical use and substitution of hazardous liquids with gaseous reactants or solvent.