An e-beam apparatus is disclosed, the tool comprising an electron optics system configured to project an e-beam onto an object, an object table to hold the object, and a positioning device configured to move the object table relative to the electron optics system. The positioning device comprises a short stroke stage configured to move the object table relative to the electron optics system and a long stroke stage configured to move the short stroke stage relative to the electron optics system. The e-beam apparatus further comprises a magnetic shield to shield the electron optics system from a magnetic disturbance generated by the positioning device. The magnetic shield may be arranged between the positioning device and the electron optics system.