It is already known that electrostatic, magnetostatic, extremely low-frequency electric fields, and pulsed electric field could be utilized in cancer treatment. The healing effect depends on frequency and amplitude of electric field. In the present work, a simple theoretical model is developed to estimate the intensity of electrostatic field that damages a living cell during division. By this model, it is shown that magnification of electric field in the bottleneck of dividing cell is enough to break chemical bounds between molecules by an avalanche process. Our model shows that the externally applied electric field of 4 V/cm intensity is able to hurt a cancer cell at the dividing stage.