Abstract: The influence of electric field on the evaporation/ boiling heat transfer characteristics for an evaporator with rectangular micro-channels was experimentally investigated. R141 b was used as the working fluid. The operating pressure was 1.01 × 10⁵ Pa. Experimental results show that electric field has an significant effect on the thermal performance of the evaporator. The heat transfer enhancement effects increase with the increase of the electric field. Under applied electric field intensity, the heat transfer efficient enhancement factor can reach as high as 0.7. The change of heat transfer efficient enhancement factor is leveling off under higher heat flux.