A writing apparatus includes a writing unit to include a deflector for deflecting a charged particle beam and write a pattern on a target object by the charged particle beam, a decision unit to decide a representative position of a deflection result range in which the charged particle beam was deflected with respect to a writing direction by the deflector, and a correction unit to correct drift of the charged particle beam by using a drift amount at the representative position of the deflection result range.

A lens element of a charged particle system comprises an electrode having a central opening. The lens element is configured for functionally cooperating with an aperture array that is located directly adjacent said electrode, wherein the aperture array is configured for blocking 5 part of a charged particle beam passing through the central opening of said electrode. The electrode is configured to operate at a first electric potential and the aperture array is configured to operate at a second electric potential different from the first electric potential. The electrode and the aperture array together form an aberration correcting lens.