The resent study is concerned with the structure of porous silicon carbide (PSC) layers fabricated on 6H-SiC substrates produced by CREE Research and differ from each other by the defects presented (Type I and Type II). For Type I samples, the current density at the electrochemical etching was 20, 60, and 100 mA/cm(2), whereas for Type II samples a lower current density-5, 10, and 15 mA/cm(2)-was used because of the presence of a large number of voids. It is shown that porous layer characteristics (pore size, porosity, layer thickness) depend on the structure of the initial substrate to a large extent.