The results of investigation of the influence of encapsulation on the mechanism of thermal decomposition of cyanide transition metal complexes, based on data obtained by methods of differential thermal analysis (inert atmosphere) and thermodesorption (mass-spectral monitoring of gaseous products) are represented. It was established, that encapsulation of cyanide iron(II) and cobalt(III) complexes in faujasite type zeolite results in the hydrolytic mechanism of thermal destruction of complexes, unlike to bulk analogues, which is determined by essential decreasing of the temperature of complex anions encapsulated destruction beginning, up to temperatures while zeolite water molecules are saved; the gaseous products of thermal destruction composition is determined by the peculiarities of localization of cations of different nature in inclusion compounds.