The bachelor thesis focuses on possibilities of analyzing unknown substances and processes generally known basic analytical methods. Furthermore, it deals with the possibilities of combining these methods in order to improve or hasten the analysis and use of the methods in the field of fire engineering. The aim of this work is to create an overview and clarify the methodology of selected chromatographic and spectroscopic analytical methods, clarify the procedure of sampling and correct sample preparation for the required type of analysis, approximate modern methods of analyzing substances and instruments that are commonly used in fire engineering not only in laboratory conditions but also in the field. The portable unknown substance determining devices, such as ED-XRF spectrometer, are described in the thesis. This device is suitable for solid, powdered or liquid substance analysis. Another device suitable for examining liquids, gels, foils, powders or solid samples is a portable FTIR spectrometer and a portable gas chromatograph with mass detector that allows the analysis of volatile compounds as well.