Electrostatic dust collector for use in vacuum system

An electrostatic dust collector (K1, K2) including a wall (1) enclosing a vacuum chamber (C) in which a target face (9a) to be subjected to dust removal is provided, an electron beam emitting device (2) for emitting electron beams to dust (13) on the target face (9a) so as to charge the dust (13) negatively, a dielectric member (10) which is provided in the vacuum chamber (C) and has a collecting face (10a) confronting the target face (9a) and a member (11, 12) for imparting positive potential to the collecting face (10a) such that the dust (13) charged negatively is attract­ed to the collecting face (10a).