A charged particle beam apparatus is provided, which comprises a charged particle beam column for generating a primary charged particle beam; a focusing assembly, such as a charged particle lens, e.g., an electrostatic lens, for focusing the primary charged particle beam on a specimen; a detector for detecting charged signal particles which are emerging from the specimen; and a deflector arrangement for deflecting the primary charged particle beam. The deflector arrangement is arranged downstream of the focusing assembly and is adapted for allowing the charged signal particles passing therethrough. The detector is laterally displaced with respect to the optical axis in a deflection direction defined by the post-focusing deflector arrangement.