This study aims at further improvement of evaporation or boiling heat transfer using an electric field. Active enhancement using an electric field would be extremely effective in film boiling, but favorable effects would be expected on nucleate and transition boiling, and on the maximum and minimum heat fluxes. In this paper the results of our preceding studies are first summarized. We have found that the application of an electric field enhances, to a great extent, the evaporation of a liquid drop on a hot solid surface. The time needed for a single drop to evaporate completely reduces to one-twentieth of that for evaporation without an electric field, when 300 V is applied to a drop of ethanol. The results of an additional experiment are presented in this paper. The heat transfer coefficient during evaporation of a liquid drop on a platinum surface is measured while the volume of the drop suspended at the tip of a thin needle nozzle is kept constant. The voltage applied between the drop and the heat transfer surface is varied from 0 V to 2000 V (for R113) or to 250 V (for ethanol). The maximum enhancement ratios of the evaporative heat transfer coefficients at the highest voltages are 7.6 for ethanol and 2.8 for R113.