Analysis of technical state of the park of electrolyzers at national aluminium enterprises has been realized. It has been educed, that 19.3% are electrolysers with Soderberg anode and with side feedthrough, 60.4% — with top feedthrough, 20.3% — with baked anodes. Replacement of electolyzers with Soderberg anode by modern electrolyzers demands more than 11 mlrd of USD in the industrial branch scale. In this connection procedures of modernization of electrolyzers with Soderberg anode and with top feedthrough has been considered. It provides improvement of technical state of such construction of electrolyzers and their technological parameters, improvement of ecology safety of production: improvement of construction of cathode device, replacement of counterforce case on rib one, cooling of anode surface et al.