The diagnosis of gastric cancer has made remarkable progress in the last 20 years, thanks to the establishment of diagnostic methodology including double contrast radiography, endoscopy (gastrocamera and fiberscope), and endoscopic biopsy. The treated number of early gastric cancers began to account for more than 50% around 1985 in the majority of Japanese institutions which specialized in gastroenterology. It is considered that the improvement of the treatment result is mostly due to the increasing number of early gastric cancers, although the progress in surgery for advanced cancer may also be a contributing factor. Now endoscopic mucosal resection has become a common treatment method for small early cancer, and the use of laparoscopic surgery has been increasing. We are now in an era seeking for rationalization of treatment options in view of reductive and function preserving surgery.