A room or facility where creative or production work is done, such as art, film, or crafts.
He is painting in the studio.
I visited the film production studio.
スタジオ is a loanword used broadly for photography, recording, or TV studios, while 制作室 is a native compound emphasizing the production aspect.
Compound of 制作 (production) and 室 (room). The exact historical derivation is straightforward; the word follows standard Sino-Japanese compounding patterns.