O&M Network (Operation and Maintenance Network) is supported by WHO’s unit for Water, Sanitation and Health (WSH) and funded by Ministry of Health,Labour and Welfare,Goverment of Japan(MHLW).The coordinator is National Institute of Public Health (NIPH). O&M Network are constituted by experienced and knowledgeable volunteers from developed and developing countries and led by O&M Network Core Groupe Members and Japanese Collaborative Members.