A short description of thermo-IR-spectroscopy analysis is given together with some examples of the interactions between hazardous organic pollutants and clay minerals. Self-supported films of organo-montmorillonite and laponite complexes can be heated in a vacuum cell and the IR spectra of the samples recorded at different temperatures. Organo complexes of other clay minerals can be heated as alkali-halide disks. In this case the effect of the alkali halides on the stability of the organo-clays and on thermal reactions should be taken into consideration. This method is useful for determination of the fine structures of organo-clay complexes. It can be applied to obtain information on the adsorption mechanism of organic pollutants by clay minerals and on the types of bond which are obtained between adsorbed hazardous species and functional sites on the clay surfaces.