The TV series, produced by "P" Productions, aired on Fuji TV from July 4, 1966 to September 25, 1967, with a total of 52 episodes. It was the first color tokusatsu TV series ever produced in Japan, beating Ultraman to the airwaves by 6 days.
The show later aired in the U.S. in the 70s, dubbed in English, as The Space Giants. It was renamed as Monsters from Outer Space and Space Avengers in the rest of the world.
The series was remade as a 13-episode OVA series in 1992-1993.