ALMA operations are carried out by three institutes appointed as Executives on behalf of East Asia, Europe, and North America, in cooperation with the Joint ALMA Observatory in Chile. The East Asian Regional ALMA Support Center (EA-RASC), as the main point of contact for East Asian researchers, provides support for the observational studies with ALMA for the East Asian user community, and conducts various activities such as engineering, development, computing, scientific observation support, research promotion, education and public outreach, etc.

After the construction budget of ALMA was approved by the Japanese government, the East Asian ALMA Project Manager was assumed by Tetsuo Hasegawa (April 2004 - March 2008) and Satoru Iguchi (April 2008 - September 2018). The current Project Manager is Alvaro Gonzalez.

The NAOJ Chile Observatory is responsible for the management of NAOJ research activities in Chile. Currently, there are about 110 staff members (roughly 20 in Chile, and 80 in Mitaka) who belong to the NAOJ Chile Observatory or the Advanced Technology Center (ATC) as researchers carrying out researches with ALMA and ASTE, as well as engineers, technicians, and administrative staff working for the ALMA/ASTE operations.

The ALMA Division of the NAOJ Chile Observatory, located at the NAOJ headquarters in Mitaka, provides support for operations and maintenance of ALMA. The East-Asian ALMA Regional Center has its office in the ALMA Division of the NAOJ Chile Observatory.

The NAOJ Chile Observatory was established in April 2012. The initial Large Millimeter and Submillimeter Array (LMSA) project office was launched established in 1997 and it has grown into the provisional Japanese ALMA (ALMA-J) project office (from April 2000 to March 2004), and then the ALMA-J project office (from April 2004 to March 2012). The ALMA-J Directors over these periods were assumed by: Masato Ishiguro; Tetsuo Hasegawa; and Ken’ichi Tatematasu. After the establishment of the NAOJ Chile Observatory, the first Director was Tetsuo Hasegawa who was succeeded by the present Director Seiichi Sakamoto.

Another telescope operated by the NAOJ Chile Observatory is the 10-meter telescope ASTE（Atacama Submillimeter Telescope Experiment）which is located at an altitude of 4800 meters close to ALMA. ASTE started its observation from 2004 as the first large full-fledged submillimeter telescope in the southern hemisphere. As a pathfinder for ALMA, ASTE not only has a mission to explore the unknown southern sky that cannot be observed from Japan, but also provides functions as a test bed for advanced observing instruments. ASTE is also important in providing opportunities for development of new equipment and in nurturing young researchers who will play key roles in radio astronomy for the next generation.

ASTE website