Based on the experience of the characterization of steel materials for more than 20 years, the author reviewed the roles and contributions of surface science in the steel industry. Surface analytical techniques have played many important role in steel industry. Surface analytical technique include not only X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and secondary ion mass spectrometry (SIMS) but scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron probe micro analysis (EPMA), x-ray diffraction (XRD), Raman spectroscopy, and so on. Surface analysis applied fields of steel investigation are surface segregation, grain boundary segregation, corrosion, surface treatment, surface passivation, and so on. Recently, the needs of the analysis of buried interface such as the interface between matrix and nano-particle or nano-grain boundary have been increased. So the three dimensional analysis with atomic resolution attracts much attention in the area of steel industry.