Tunnelingspectroscopy of Au(100)‐(5×20) and Fe on Au(100) surfaces has been studied. Using a well‐defined tunneling tip, I–S, I–V, and V/I*d I/d V–V spectra were obtained. The results confirm that the characteristics of the spectra resemble those of previously reported semiconductors. From I–S relations, it was found that the tunneling barrier decreases abruptly when the tunneling gap is <6 Å.