Influence of electric field on thermal resistance of the closed-loop pulsating heat pipe (PHP) has been investigated experimentally. PHP is made from a long capillary copper tube with inner diameter of 1,9 mm and outer diameter of 3,0 mm bent into a planar serpentine with five U-turns filled with n-hexane. High voltage electrodes are located in the evaporation zone. Measurements of temperatures have been performed for range of 5-50 W applied heating power and for range of 5-18 kV DC voltage. At the heat input of 20 W and a voltage of 18 kV, a reduction in the thermal resistance of the PHP by 35% was obtained. A generalization of the obtained experimental data has been carried out. The temperature of the evaporation zone could be controlled within certain limits using the electric field, which can be used for thermostatting.