A multi-beam inspection apparatus supporting a plurality of operation modes is disclosed. The charged particle beam apparatus for inspecting a sample supporting a plurality of operation modes comprises a charged particle beam source configured to emit a charged particle beam along a primary optical axis, a movable aperture plate, movable between a first position and a second position, and a controller having circuitry and configured to change the configuration of the apparatus to switch between a first mode and a second mode. In the first mode, the movable aperture plate is positioned in the first position and is configured to allow a first charged particle beamlet derived from the charged particle beam to pass through. In the second mode, the movable aperture plate is positioned in the second position and is configured to allow the first charged particle beamlet and a second charged particle beamlet to pass through.