The specific features of applying electrochemical capacitance–voltage profiling to investigate heavily doped structures with a sharp doping profile are considered. Criteria are presented, and recommendations are given for selection of the optimal measurement parameters, and the necessity of increasing the frequency, at which the capacitance is measured during profiling, is substantiated. The described procedure is considered by the example of profiling p -type silicon structures with ion implantation as well as n -GaAs epitaxial and substrate structures for p HEMT devices.