The aim of this book was to create a FT - IR database of heterogeneous inorganic samples. The contents of the theoretical part include an introduction to infrared radiation and display the theoretical basis for measurement in a concise form. The experimental part consists of two areas. The first area focuses on the measurement of IR spectra of chosen samples. The measured samples are mostly based on silicon dioxide. The second area of the experimental part studies the influence of the selected method of measurement on the results of the measurement. The experiment examines two methods of measurement of the IR spectra, one being carried out with the use of KBr tablets and the other using the ATR accessory. Both of these methods were measured in the middle infrared and far infrared region.