We describe the concept of a new instrument for the Canada-France-Hawaii telescope (CFHT), SITELLE (Spectromètre
Imageur à Transformée de Fourier pour l'Etude en Long et en Large de raies d'Emission), as well as a science case and
a technical study of its preliminary design. SITELLE will be an imaging Fourier transform spectrometer capable of
obtaining the visible (350 nm - 950 nm) spectrum of every source of light in a field of view of 15 arcminutes, with 100%
spatial coverage and a spectral resolution ranging from R = 1 (deep panchromatic image) to R = 104 (for gas dynamics).
SITELLE will cover a field of view 100 to 1000 times larger than traditional integral field spectrographs, such as
GMOS-IFU on Gemini or the future MUSE on the VLT. It is a legacy from BEAR, the first imaging FTS installed on
the CFHT and the direct successor of SpIOMM, a similar instrument attached to the 1.6-m telescope of the Observatoire
du Mont-Mégantic in Québec. SITELLE will be used to study the structure and kinematics of HII regions and ejecta
around evolved stars in the Milky Way, emission-line stars in clusters, abundances in nearby gas-rich galaxies, and the
star formation rate in distant galaxies.