The indications for endoscopic treatment have expanded in recent years,and relatively intestinal-type mucosal stomach carcinomas with a low potential for metastasis are now often resected en bloc by endoscopic submucosal dissection(ESD),even if they measure over 20 mm in size.However,ESD requires complex maneuvers,which entails a long operation time,and is often accompanied by complications such as bleeding and perforation.Many technical developments have been implemented to overcome these complications.The scope,cutting device,hemostasis device,and other supportive devices have been improved.However,even with these innovations,ESD remains a potentially complex procedure.One of the major difficulties is poor visualization of the submucosal layer resulting from the poor countertraction afforded during submucosal dissection.Recently,countertraction devices have been developed.In this paper,we introduce countertraction techniques and devices mainly for gastric cancer. The indications for endoscopic treatment have expanded in recent years, and relatively intestinal-type mucosal stomach carcinomas with a low potential for metastasis are now often resected en bloc by endoscopic submucosal dissection (ESD), even if they measure over 20 mm in size. However , ESD requires complex maneuvers, which entails a long operation time, and is often accompanied by complications such as bleeding and perforation. Many technical developments have been implemented to overcome these complications.The scope, cutting device, hemostasis device, and other supportive devices have been improved. Even before even these innovations, ESD remains a poor complex procedure. One of the major difficulties is poor visualization of the submucosal layer resulting from the poor countertraction afforded during submucosal dissection. Recently, countertraction devices have been developed. in this paper. , we introduce countertraction techniques and devices mainly for gastric cancer.