The invention relates to a particle beam apparatus comprising: a particle beam source configured to generate a particle beam; a magnetic coil configured to emit a magnetic field to manipulate the particle beam; an object table configured to hold a substrate; a positioning device comprising ferromagnetic material, the positioning device further comprising at least one motor configured to position the object table with respect to the particle beam; and a controller configured to provide a control signal to the at least one motor to at least partly compensate for a magnetic force induced by the magnetic field acting on the positioning device.

An improved method and system for correcting inspection image error are disclosed. An improved method comprises acquiring a set of first beam positions on a test wafer while a wafer stage supporting the test wafer moves at a first velocity; acquiring a set of second beam positions, corresponding to the set of first beam positions, on the test wafer while the wafer stage moves at a second velocity; calculating a beam position displacement of a beam while the wafer stage moves at a third velocity in a range of velocities from the first velocity to the second velocity; and adjusting a beam position of the beam based on the calculated beam position displacement.