A simple infrared cell was developed to study gas adsorption on a catalyst. The main body of the cell was made of Pyrex glass. Windows were attached to the cell body by means of O‐ring seals with water‐cooled brass rings. A heating assembly with tungsten windings was set in the cell. This cell could be used at temperatures up to 450°C, either under vacuum to a pressure of 10−6Torr or in any controlled atmosphere.