Аннотация:The overview of the main scientific achievements of Aida Andreevna Kovtun, Professor of the Department of Physics of the Earth, Physical Faculty of SPbSU, is presented. The resuts of her long time studies of crustal structure of the Russian North-West with a help of electromagnetic geophysical methods are discussed. She investigated the Lake Ladoga conductivity anomaly, has revealed and studied conductive layers in the Earth crust of the Fennoscandian (Baltic) Shield. А.А. Kovtun was the teacher of several generations of University students and supervisor of more than a dozen of Philosophy Doctors in Geophysics.