A trapping device is presented to improve production efficiency of vacuum processing devices. The trapping device comprises an exhaust path for evacuating process gas from a hermetic chamber through a vacuum pump; a regeneration path disposed adjacent to the exhaust path and comprising a regeneration means; not less than two trap sections communicable either with the exhaust path or with the regeneration path; and switching means for transposing the trap sections either to the exhaust path or to the regeneration path. A trapping operation and a regeneration operation can be performed concurrently respectively in the exhaust path and the regeneration path.