Abstract: A stack of aligned workpieces is placed in a frame body, and a mask is positioned over the stack of workpieces in alignment therewith. The frame body is then moved into an exposure device in which the mask is transferred from the frame body onto a transparent plate and the workpieces are transferred successively from the frame body onto the transparent plate. The workpieces are exposed successively to the mask. The exposed workpieces are then discharged successively out of the exposure device. The mask is transferred from the transparent plate back to the frame body after all of the workpieces have been exposed. The frame body with the mask carried therein is moved out of the exposure device.