In this study, pilot pervaporation experiments of ethanol dehydration from the vapor phase feed have been carried out. The dehydration time decreased with increasing of the feed temperature and did not vary with the feed flow rate. The temperature dependence of permeation rate in vapor phase feed was larger than that in liquid phase feed. Contrary to the pilot pervaporation of liquid phase feed, the higher the feed flow rate, the larger the temperature drop is. The variation of temperature drop with permeate flux in vapor phase feed is larger than that in liquid phase owing to the heat loss of the membrane module itself.