One of the useful methods for stabilizing field emission current in field emitter arrays (FEAs) is to control them using field effect transistors (FETs) connected in series. However, one cannot use conventional FETs, because the electron extraction voltage (ypically hundreds of volts) of FEAs is much higher than the permitted source-drain voltage of FETs. The authors conducted a detailed investigation of the mechanism for current stabilization of the field emission current while controlling the field emitter tip wtih a FET. The electron source consists of the FET controlled tip and surrounding electrode, which is kept at a constant potential. In this paper the authors discuss how the field enhancement factor (beta) is modified by the potential distribution, which is determined by the potentials of the tip and the surrounding electrode, Making use of this effect, the authors could control a FEA that has a high electron extraction voltage with a FET with a lower source-drain voltage. (c) 2008 American Vacuum Society.