We have investigated electrochemical etching for alpha-(6H and 4H) SiC (0001) using aqueous HF and HF+HNO3 solutions. 4H- and 6H-SiC (0001) Si faces were electrochemically etched at room temperature using hydrogen fluoride based electrolytes. In the case of HF solution, etched surface with a small roughness of 0.5 nm was obtained compared with surface before etching. In the case of HF + H2O electrolyte with pH=3.5, SiC was etched for 1 mum depth in 60 min. While, in the case of HF+HNO3+H2O electrolyte, etching was not confirmed and a thin film involving Si-O-C bonds was formed. In the case of HF+HNO3 solution, a thin film with 2similar to3 mum thickness was formed in the entire pH range for 60 min. The pH value decreased after the electrochemical process in both solutions, indicating the decrease of OH- ions. Based on these results, electrochemical etching mechanisms in the alpha-SiC were discussed.