ELECTRICAL SURGICAL DEVICE

PROBLEM TO BE SOLVED: To perform a surgical treatment on a living body and to properly and optimally coagulate the affected part. SOLUTION: An electrocautery device, one of the electrical surgical instruments, consists of a controller 10, a high frequency current control circuit 30, and a handpiece 34. The handpiece 34 is provided with an infrared temperature sensor 32 (temperature sensor) in addition to a blade 36. This sensor 32 measures the average temperature of the affected part (coagulation area 42 formed on the living body 40) and outputs the temperature to the controller 10 (output unit). In the controller 10, the temperature is shown on a display 14, and/or the output of the high frequency current control circuit 30 is controlled so that the temperature of the affected part becomes a target temperature. On the basis of the temperature of the affected part thus measured, a surgical treatment can be performed properly. Consequently, in performing a surgical treatment on the living body, the affected part can be coagulated properly and optimally.