The synthesis of composite materials based on silver nanotubes and PET track-etched membranes (TMs) has been studied. A systematic study of the catalytic properties of the resulting composites has been conducted using the example of the hydrogen peroxide decomposition reaction. Changes in the catalytic properties of the composites as a function of the pore density of the initial PET template and the duration of the chemical template synthesis of silver nanotubes have been analyzed. The Ag/PET TM structure has been studied by SEM; the phase composition and the crystallite sizes have been analyzed by X-ray diffraction. To study the kinetic parameters of the reaction in a temperature range of 25-45A degrees C, the activation energies of both the composite samples and the PET film with silver nanoparticles deposited on the surface have been calculated; it has been found that the lowest activation energy is exhibited by Ag/PET TM composites with a pore density of 1 x 10(9) ion/cm(2). Optimum synthesis conditions providing the formation of Ag/PET TM composite catalysts that preserve their integrity and mechanical strength during testing and mediate the studied reaction at the highest rate have been determined. The stability of the catalyst properties has been studied; it has been shown that, at 25A degrees C, the catalyst activity decreases by 35% after the third test run.