Spectroscopy is the study of the interaction between matter and electromagnetic radiation. In this paper, the absorption spectra of near infrared radiation will be analyzed (the Near-infrared light ranges from 750 nm to 2500 nm). Since the obtained spectra can determine the content of a certain substance in the liquid sample. In particular, it allows you to determine the content of alcohol in alcoholic beverages, since the methyl groups (C-H) contained in alcohol, absorb waves from the NIR region. It can be seen in the spectral diagram. However, the absorption bands in the reduced region are very wide, which makes the spectrum difficult to analyze. Therefore, to obtain the information, it is necessary to apply the multivariate calibration techniques, in which reference data are used to analyze the obtained spectra. Also in this article іs described the structure and hardware setup of the optical device used for measuring.