Kushiro Coal Mine is located in southeast of Kushiro-City, Hokkaido, Japan and the only underground as well as under seabed coal mine. Paleogene Harutori Coal Bearing Formation is mined over the long period. During the mining, associated methane gas called as Coal Mine Methane (CMM) is extracted for safety reasons. In addition, another type of methane from the Cretaceous is also extracted, and mixed with CMM. Taking these factors into consideration, Kushiro Coal Mine has researched and studied for the development of gas collection technique and effective utilization system. As part of the investigation, Kushiro Coal Mine and Osaka Gas have promoted the effective utilization by gas concentration technique using Pressure Swing Adsorption, and the whole system has operated in 2017. The purpose of this article is to review general design of the gas concentration project of Kushiro Coal Mine.