Disclosed are an electrode for high-frequency surgery, a high-frequency surgery device, and a method for controlling same, wherein the electrode for high-frequency surgery can be easily inserted and moved inside the lumens inside the body, and can expand a conduction area of a high-frequency current after reaching an area to be treated. The electrode for the high-frequency surgery, according to the present invention, comprises: a balloon and a conductive structure, which is arranged on the outside of the balloon and the exterior shape of which varies according to the volume of the balloon.
