A novel design for an electrochemical cell for in situ atomic force microscopy (AFM) electrochemical measurements with constant volume guard is presented. Decrease in the solution volume during experiments can affect the electrochemical as well as the scanning probe results. The cell is designed for a force microscope with a stationary sample and a scanning probe. Most existing AFM-electrochemistry cells are limited to small volumes and suffer froin high rate of solvent evaporation. The new design enables imaging in small or large volumes under constant volume conditions. Electrochemical measurements using a redox marker in a 0.2 and 2mL cells, with and without the constant guard, are presented.