The invention relates to an electrode stack (70) comprising stacked electrodes (71-80) for manipulating a charged particle beam along an optical axis (A). Each electrode comprises an electrode body with an aperture for the charged particle beam. The electrode bodies are mutually spaced and the electrode apertures are coaxially aligned along the optical axis. The electrode stack comprises electrically insulating spacing structures (89) between each pair of adjacent electrodes for positioning the electrodes (71-80) at predetermined mutual distances along the axial direction (Z). A first electrode and a second electrode each comprise an electrode body with one or more support portions (86), wherein each support portion is configured to accommodate at least one spacing structure (89). The electrode stack has at least one clamping member (91-91c) configured to hold the support portions (86) of the first and second electrodes, as well as the intermediate spacing structure (89) together.