The electrochemical stability of SAMs prepared from dodecanethiol (1), (N-2'-mercaptoethyl)-amino)octaneamide (2) and ((N-(2'-mercaptoethyl)-amino)carbonyl)azobenzene (3) in ethanol was studied. The results reveal that introducing hydrogen bonds into SAMs could effectively increase their stability in electrical environment. The presence of large rigid aromatic group in the film may, however, cause a decrease of stability.