Asia has been the scene of rapid economic development. One result of this development has been the mounting severity of environmental problems. The cooperation of advanced industrial countries is indispensable for resolving the environmental problems in developing countries. Japan is providing cooperation to Asia countries through the Green Aid Plan conducted by NEDO and other groups, and promoted by MITI, Japan is also transferring environmental and energy-saving technology that was developed to deal with its pollution problems and the oil crisis. This report will describe the adoption of an energy-saving system in a steel mill in Indonesia.