Youths and kids in Indonesia since almost two decades ago have been showing significant increase of interest in space sciences, especially astronomy. One of the main factors is due to the annual event of National Science Olympiad which includes Astronomy as the subject. The increasing level of public interest, especially younger generation on astronomical events, such as eclipses, moon sightings, meteor showers has been constantly observed from time to time. Being aware that Astronomy course does not included in primary and secondary education level’s curricula, teachers are somewhat desperate and are not capable to play role as clearing house in science related to space. The IAU Network of Astronomy for School Education Network (IAU-NASE) course was started in 2016 in Machung University, East Java as the pilot project in Indonesia. The course has attracted significant interest from teachers and university staff, especially in East and Middle Java Provinces. Being confident with the enthusiasm of teachers who expressed that NASE course could fulfil their needs to teach and instruct students in a very efficient way, it was organized consecutively at Bandar Lampung, Lampung Province in 2018 and 2019 (hosted by Institut Teknologi Sumatera) and in 2020 at Bandung, West Java Province (hosted by Institut Teknologi Bandung). The most recent NASE course on 21–23 August 2020, conducted in on-line mode, was attended by 74 participants, although primarily aimed at 15 School teachers, and was quite successful. The on-line observational activity turned out to be the most impressive session for the participants. We report and review four years of IAU NASE courses in Indonesia, with various documentation and brief analysis of the positive impact to the teachers and instructors attitude in teaching astronomy at secondary level of education.