The recent increase in the detection of esophageal mucosal cancer has been changing the direction of treatment. The rate of esophageal cancer detection in mass screening by X-ray is 0.008%, which is 1/13 that of gastric cancer. Moreover, the rate by endoscopy is higher; the former is 0.1% and the later is 0.6%. Further, endoscopic screening using iodine staining for a high risk group like alcoholism has 3.6% detectability on esophageal cancer and 1.7% on gastric cancer. The rate of cancer-detection of upper intestinal organs comes to 5.35% in all. Most of the esophageal cancer detected by endoscopy is mucosal cancer, which is treatable by endoscopic mucosal resection (EMR). The result of the treatment is 100% 5 year-survival in cases of m1 and 2 esophageal cancer. EMR of esophagus-preserving treatment is truly effective for patients. Endoscopic examination using iodine staining for the high risk group is excellent for mass screening of esophageal cancer.