MIRI (Mid InfraRed Instrument) is 1 of the 3 scientific instruments of the new space telescope named JWST (Jawes Webb Space Telescope) that will take over the HST (Hubble Space Telescope) currently used by the astronomy international community. The JWST with its enhanced performances (6.5 m diameter mirror compared with a 2 m diameter mirror on the HST for example) intends to see the "first light in the Universe", that is to scrutinize the sky around 13 billions years in the past. It will also be able to observe the formation of stars in the molecular clouds, the formation of solar systems around other stars and see Jupiter-like or larger planets around stars. The JWST will not orbit the Earth as the HST, but will be placed around the L2 Lagragian point of the Earth Sun system.

The JWST is developed under the NASA responsibility in cooperation with the Canadian Space Agency (CSA) and the European Space Agency (ESA). MIRI is developed under ESA and national space agencies responsibility by a European Consortium of laboratories.

MIRI itself is composed of 2 main parts: the spectrometers lead by Dutch and British and the imager MIRIM lead by French. But 7 other countries are participating: Belgian (electronics, calibration optics, mirrors), Danish (structure), German (cold mechanisms), Irish (dichroics), Spain (simulator), Swedish (filters), Swiss (harness, covers).