Gastroenterologists often follow up second look endoscopy after endoscopic submucosal dissection(ESD) of gastric neoplasms because they want to prevent bleeding of procedure sites. But Goto suggested in his retrospective analysis that a second-look endoscopy after endoscopic submucosal dissection for gastric epithelial neoplasm may be unnecessary. So, the investigators try to identify the hypothesis prospectively in this study.