Abstract: An accessory for an FTIR spectrometer comprises fiber-optic cables connected to a framework within which two mirrors are housed. The mirrors, which are preferably off-axis parabolas, are positionable with respect to each other and with respect to the ends of the fiber-optic cables. The beam from the first cable is reflected by the first mirror onto a sample surface at or near the grazing angle, after which it is captured by the second mirror and focused onto the end of the return cable which transmits it back to the spectrometer. Very thin films and coatings can be spectroscopically detected and characterized using the accessory.