Relevance. Toward electrodischarge technologies, interest is being shown by various sectors, including construction, because of environmental safety and the capability for precise control of energy impact. Recently, this interest has grown markedly due to the sharp rise in ecological problems and increased attention to developing new ecologically clean technologies. Currently, these technologies are being actively studied in major laboratories across developed countries. Modern analysis shows that despite improvement of tools for destruction of rocks, wear of equipment and high costs at depths limit effectiveness of traditional methods, which are approaching their technical limit. The use of electrodischarge technologies shows promise for drilling wells in hard rock formations, demolishing concrete and reinforced concrete structures, crushing various non-conductive materials, and extracting valuable minerals from ore. The emergence of an insulating material capable of long-term operation as high-voltage insulation for electrodes in water could give a significant boost to the development of electric discharge technologies for drilling, crushing, cutting, and surface layer removal. Aim. Creation of insulating material with specified dielectric permeability, with high resistance to impact of partial and surface discharges, capable of withstanding high temperatures during operation in electric discharge technologies for their wide introduction into industry. Methods. Modification of silicone rubber compound IRP 1338 through addition of barium titanate (BaTiO3) and powder with the chemical composition K_xFe_yTi_8-yO₁₆ (x=1.4–1.8, y=1.2–1.6). Results and conclusions. The authors have proposed and conducted the researches on modification of silicone rubber mixture IRP 1338 for increasing the specified values of dielectric permeability. They achieved the increase of dielectric permeability to 23.8 at frequency of 1 МHz.