Although the flexible endoscopy has been widely used in the medical field for many years, there is still great potential in improving the endoscopist's capability to perform therapeutic tasks. Tentatively, tools for the flexible endoscope have poor maneuverability and limited Degree Of Freedom (DOF). In this paper, we propose a surgical robotic system MASTER (Master And Slave Transluminal Endoscopic Robot). MASTER is a dexterous and flexible master-slave device which can be used in tandem with a conventional flexible endoscope. Using this robotic system, ESD (Endoscopic Submucosal Dissection) and NOTES (Natural Orifice Transluminal Endoscopic Surgery) have been conducted on in vivo and ex vivo animal trials with promising results.