A microtechnique for obtaining the infrared spectra of solids and corrosive liquids, utilizing sample weights as low as 4 micron grams, is described. A cell in which diamonds or sapphires are used as window material is employed to obtain spectra in the 2- to 35-micron region. The visible and ultraviolet regions can also be studied. Spectra are obtained routinely, easily, and rapidly without many of the limitations inherent in other procedures. So far is known, the method is applicable to all solids.