The fluid velocity and temperature fields in a fluorine production cell were studied using the finite element method. The trajectories of the hydrogen bubbles evolving from the cathode within the cell were investigated based on the concept of hydrodynamic diffusion. To reduce the ohmic voltage loss between the electrodes, a quantitative examination was made of the effect of changing the configuration of the slits formed on the cathode, such as the locations, inclination, size, and number of the slits, on the escape of the hydrogen bubbles toward the rear of the cathode. This quantitative examination was performed by calculating the normalized distribution function of the bubbles. The results showed that the cathode configuration has a profound effect on both the flow pattern near the cathode and the bubble trajectories. (C) 2003 The Electrochemical Society.