CHF-B260 has thinner diameters, and the quality of the endoscopic images has improved. Recently, narrow band imaging (NBI) system has been developed for high-contrast observation of mucosal structures and vascular patterns. It is available to diagnose for the bile duct cancer endoscopically and it is useful for desciding of surgical margin before operation. As for its applicability to investigating the progression of superficially infiltrated bile duct cancer, additional cases must be examined in the future.