The experimental results of this paper refer to the kinetics of the decomposition process of 1,3-diisopropylbenzene dihydroperoxide (HPO) on a catalyst of montmorillonite type containing Cu2+ ions. Between 22 and 56 degrees C the kinetic studies show a process having the rate equation to be characteristic of first order reactions. The activation energy (E-a = 50.7 kJ/mol), the enthalpy of activation (Delta H-# = 43.5 kJ/mol), the entropy as well as the Gibbs free energy of activation were calculated for the temperature region in which the kinetics of the process was studied. Resorcinol and acetone were yielded by this chemical decomposition. Both compounds are important intermediates of the chemical industry. The catalyst has high activity and is really useful for such chemical purposes. It has high stability as a result of its mineral nature. Application of this catalyst can avoid using aqueous acids which are strong pollutants of the environment.