The development of manganese nodule mining technology is very important in order to secure a long-term and stable supply of rare strategic metals. In the twenty years following the R&D activities with the international consortia in the 1970s, studies on mining technologies have been carried out by several national projects in Korea. The current metal prices such as copper, nickel, cobalt, and manganese have been drastically changed since 2002. Rapid economic growth of Asian countries, especially China, have induced the situation. And the possibility of copper shortage is looming just around the comer. Because of the imbalance between production and consumption, copper is fundamentally the most threatened metal in the future in terms of potential metal shortage. Manganese nodules contain a considerable percentage of copper as the future metal resource. Therefore, it is necessary to concentrate our effects on developing these resources. This paper introduces our evaluation of R&D progress for the development of manganese nodules. The issue and role of manganese nodules during the difficult period of a potential future metal shortage period is discussed and its prospect outlined. Also, this paper tried to emphasize the necessity of continuous R&D efforts for the commercial development of such mineral resources.