Oxidation and pyrolysis processes of brewing industry waste have been researched. Elemental composition and technical characteristics of the investigated sample were determined with the help of elemental analyzer and standard methods. Thermal transformation of the sample was performed by the method of thermogravimetric analysis at the heating rate of 10 °C/min up to the maximum temperature of 700 °C. Air and argon with flow rate of 150 ml/min were used as blown gas. Thermal analysis data (DTG curves) were used to determine the process stages which correspond to mono- or bimodal release of volatile compounds and oxidation of the resulting carbon residue (for oxidation mode). The characteristic temperatures of the beginning and end of oxidation (Ti=242 °C and Tf=612 °C) and pyrolysis (Td=255 °C and Tf=460 °C) as well as the reaction time and rate were determined. The qualitative analysis of gas-phase products of thermal conversion of the sample was performed by the mass spectrometry method. The activation energy values of the processes under consideration were calculated by the Coats-Redfern method and their values were about 19 kJ/mol.