In recent surgeries, not only conventional devices such as scalpels, scissors, and tweezers but also energy devices such as electric scalpels and ultrasonically activated scalpels are frequently used. Although these devices use different energy sources, each heats biological tissue to a high temperature for a short time to incise, stem, and inosculate. Because these devices can carry out these treatments not only alone but simultaneously, they are also indispensable devices for surgery. However, they do have some problems to be solved. In this laboratory, we have been developing energy devices using microwave energy to solve these problems. Figure A shows one type of hemostatic microwave energy device that we have developed. We used the device in animal experimentation, as shown in Fig. B. Figures C-E show states of hemostasis. It was possible to stop bleeding promptly by pressing the device to the bleeding point and irradiating with microwave energy.