Process for adjusting the brightness of a microtip fluorescent screen and device for implementing this process. This type of screen is matrix-like and addressed by a line scanning, a pixel is formed at each line-column crossover. For a "lighted" pixel, for a selection time T of the corresponding line, a quantity of charge is emitted by the associated microtips. The adjusting of the brightness is performed during the selection time of each line, by controlling the quantity of charges emitted by the microtips of each pixel to be lit, this quantity of charges being identical for each pixel. Application to displaying.