The trends of gastric cancer in Korea are changing, such as an increase of early and minute gastric cancer. The standard treatment of gastric cancer has become more complicated. Endoscopic treatment of gastric cancer is considered to be a useful procedure towards a curative or conservative treatment of early gastric cancer or advanced gastric cancer. Recent advances in endoscopic treatment technique are truly remarkable. The advances allow minimally invasive treatment of diseases that would otherwise require major surgery. New techniques will continue to solve the limitations of endoscopic treatment and their use will also continue to expand accordingly.