CONCERTO, installed in April 2021 on the Atacama Pathfinder EXperiment (APEX) 12-meters telescope and covering the frequency range 100-300 GHz, inaugurates a class of instruments. The new born on the Chajnantor plateau combines the largest instantaneous field-of-view, diffraction-limited angular resolution and moderate spectral capabilities. In order to achieve this “triple jump”, without sacrificing the optimal sensitivity, a 4.300 pixels cryogenic camera has been coupled to a sophisticated optics system including a Martin-Puplett interferometer (MPI). A fast-moving (2.5 Hz) mirror allows to separate the spectral components of the incoming radiation in the Fourier domain for each individual pixel of the camera
