The variation of electric field gradient above arrays of field emissioncathodes has been investigated using atomic force microscopy. The spatial distribution of electric field gradient was obtained as a function of bias and height. Results show a parabolic relationship between the sample bias and electric field gradient. Furthermore, the height dependence of the field gradient is found to follow a power law relationship. These new results demonstrate that force‐gradient atomic force microscopy is capable of providing a direct visual presentation of the variation of field gradients above submicron‐periodicity field emitter arrays.