Abstract: A mid-IR spectrometer attachment performs reflection spectroscopy measurements using commercially available infinity corrected light microscopes without degrading the microscope's performance. The mid-IR spectrometer attachment, which is mounted to and supported by the visible light microscope, introduces infrared radiation into the optical path of the microscope. Radiation from the mid-IR spectrometer source is directed by a trichroic radiation director to a mid-IR objective lens affixed to the microscope nosepiece. The objective lens focuses the radiation on to a subject sample surface in order to acquire either internally or externally reflected infrared spectra by subsequently directing the sample encoded reflected mid-infrared radiation to the radiation director and then to a mid-infrared radiation detection system.