Abstract: The structural characteristics (structural resistance coefficient, volume porosity, tortuosity coefficient, average pore radius, specific surface area) and specific electrical conductivity of high-silica micro- and macroporous glasses with different compositions (basic magnetite-free and magnetite-containing glasses) have been studied in solutions of sodium, lanthanum, and iron(III) chlorides at a constant ionic strength. It has been found that the differences in the morphology of the pore space and characteristics of secondary silica are the reasons for different intensities of variations in the structural parameters of microporous glasses upon their long-term contact with electrolyte solutions, with the most pronounced time variations occurring in lanthanum chloride solutions. In indifferent electrolyte solutions, glass composition has no effect on the value of the efficiency coefficient. For microporous glasses in solutions containing specifically adsorbabable ions, the value of the efficiency coefficient is mainly affected by the structure of secondary silica in pore space, other conditions being equal. It has been revealed that, in iron chloride solutions, the specificity of the counterions is more pronounced for the basic porous glasses.