Electrosurgery performs cutting and coagulation procedures using high energy and high frequency electric current. It reduces bleeding during surgical interventions, shortens the operation time and accelerates the healing process. In this study, a GaN based high frequency full bridge class DE resonant inverter design is proposed for use in electrosurgery. The proposed inverter provides AC voltage at high frequencies and the switches operate with ZVS (Zero Voltage Switching) at low voltage stress. In addition, the use of GaN elements provides high efficiency and high-power density. The operating frequency is selected as 500 kHz for three different cutting modes of electrosurgery. After the technical analysis and simulation studies of the high frequency class DE resonant inverter, an experimental setup was designed and implemented in a laboratory environment. The efficiency performance over a variable load range is analysed. Finally, pure cutting, blend and coagulation modes are tested on the different loads, potato - chicken breast - liver, simulating real tissue. On the potato load for pure cutting mode, the output voltage is 39.9 V and the output current is 0.7 A while an efficiency of 35%.