Apparatus for analyzing and/or processing a sample with a particle beam and method

An apparatus for analyzing and/or processing a sample with a particle beam, the sample being a lithography mask, comprising:

• a sample stage for holding the sample;
• a providing unit for providing the particle beam comprising:
• an opening for guiding the particle beam to a processing position on the sample;
• and
• a shielding element for shielding an electric field generated by charges accumulated on the sample;
• wherein the shielding element covers the opening, is embodied in sheetlike fashion and comprises an electrically conductive material;
• wherein the shielding element comprises a convex section, this section being convex in relation to the sample stage and being curved in the direction of the sample stage;
• wherein the convex section has a through opening for the particle beam to pass through to the sample;
• and
• wherein the apparatus is configured such that the convex section of the shielding element is at a distance from the sample of at most 500 μm during an analysis or processing of the sample with the particle beam.