We report on a method to stabilize the transmitted electronflux in a field-emission electronsource using an external regulation circuit. The electron source was realized with an array of silicon (Si) nanowhiskers on the top of elongated pillar structures, amica spacer, and an extraction grid made of Si. As for most applications, the emitted electron current from the cathode is not as crucial as the transmitted electron flux through the extraction grid toward the anode. We investigated a method which allows the regulation directly by the emitted electron flux and not merely on the cathode current. By using this method, we were able to stabilize the emitted electron flux of our electron source down to values below1%. Simultaneously, it was shown that there is the possibility to stabilize the influencing value in the real applicationaswell. The effectiveness of thismethod was demonstrated successfullywith an X-ray source setup. The measured X-ray photon count rate was stabilized to a standard deviation of 0.30% at a pressure of $1\times 10^{-7}$ mbar. Even in harsh environment of $2\times 10^{-5}$ mbar, a stabilization of the X-ray photon count rate down to a value of 0.63% was achieved.