Epoxy resin‐based composite materials were investigated. Samples were made of epoxy resin ED‐20 with the addition of different amounts of microspheres. Structure and sizes of small filler particles were determined. The derived compounds were tested for resistance to alternating temperatures and corrosive media. The results demonstrated that samples with the addition of 10 % of microspheres are more resistant to the impact of 25 % acid and alkali, as well as to gasoline. At the same time, the amount of the filler from 2 to 10 wt % does not influence the resistance to alternating temperatures significantly. The conducted tests demonstrated the resistance of the developed composite materials to alternating temperatures and corrosive media, which allows using them as corrosion‐resistant coatings for metal structures and in machine maintenance.