A new and simple reference electrode has been developed which can be used for electroanalytical measurements in corrosive media. The electrode has proven useful in HF acid solutions, in other systems of extreme pH conditions, in the presence of either oxidizing or reducing agents, and in mixed aqueous–organic media, as well. The electrode is based on a stainless-steel wire immersed in an HCl electrolyte, separated from the sample solution by an ion-exchange membrane. Sulfonated ethylene–vinyl acetate copolymer films, manufactured according to a patented procedure, were used as the membrane. The electroanalytical applications of the electrode are based on its constant potential value of –0.545 V versus SCE [–0.303 V versus standard hydrogen electrode (SHE)], which is maintained over the entire pH range and in a broad temperature domain (from 281 to 344 K), with a temperature coefficient of [(–6.85 ± 0.05)× 10^–4 V K^–1]. Some of the analytical applications are demonstrated.