A charged particle beam device is described, which includes: a beam source configured to generate a charged particle beam propagating along an optical axis (A); an aperture device with a plurality of apertures configured to create a plurality of beamlets from the charged particle beam; and a field curvature corrector. The field curvature corrector includes: a first multi-aperture electrode with a first plurality of openings having diameters that vary as a function of a distance from the optical axis (A); a second multi-aperture electrode with a second plurality of openings; and an adjustment device configured to adjust at least one of a first electrical potential (U1) of the first multi-aperture electrode and a second electrical potential (U2) of the second multi-aperture electrode. Further, a field curvature corrector and methods of operating a charged particle beam device are described.