There are 17 goals and 169 targets based on the philosophy that “No one will be left behind” in Sustainable Development Goals (SDGs) adopted by the 193 nations which have joined the United Nations. And the goals to achieve by 2030 such as settlement of various social problems are set. I think that materials systems will play an important role from the viewpoint of SDGs because no product on the earth can be realized without materials. The year 2030 will come in fewer than ten years. Therefore, we must look beyond and consider what must be done from the viewpoint of materials systems to realize a sustainable society while trying the address the respective technological difficulties. Therefore, it will be necessary to optimize and perpetuate the materials circulation system. That is, we should first make machines and structures to contribute to society by using limited resources of the earth. Next, after using them to the completion of their useful life, we should extract resources from them by decomposing them. Subsequently, we should make up-to-date machines and structures again by reusing them. In order to realize that goal, I would like to consider and discuss with you together what we should do at each stage of the materials system.