A method of improving uniformity of brightness between pixels in an electron emission panel includes respectively applying a scan driving voltage and a data driving voltage to a scan electrode and a data electrode of each of a plurality of pixels, wherein one of the scan driving voltage and the data driving voltage is higher than the other; measuring a brightness of each of the pixels; and respectively applying a scan adjustment voltage and a data adjustment voltage to the scan electrode and the data electrode of each of the pixels based on the measured brightness of a respective one of the pixels, wherein a higher one of the scan adjustment voltage and the data adjustment voltage is applied to a same one of the scan electrode and the data electrode to which a lower one of the scan driving voltage and the data driving voltage is applied.