CHROMATEM is a monochromated and Cs-corrected scanning transmission electron microscope designed and built by NION based on the HERMES model, and adapted to some Orsay STEM team specifications, making it a world-wide unique machine for electron and photon spectromicroscopy techniques with ultra-high energy and spatial resolution. CHROMATEM will address cutting-edge issues and target new problems, such as low-dimentional physical phenomena, quantum nano-optics, optoelectronic properties of semiconductor nanostructures and metal-insulator transitions.