THEMIS activities are managed thanks to a dual administrative structure:
- THEMIS S.L.U, a private spanish company owned by the French CNRS INSU.
- The French-Spanish Laboratory for Astrophysics in Canarias (FSLAC; CNRS IRL2009), a joint international research Laboratory between CNRS INSU and the Instituto de Astrofísica de Canarias (IAC).