Processing apparatus

The invention is to provide a processing apparatus which can keep temperature thereof constant even a dust collector mechanism is employed. The processing apparatus includes: a processing bench, whichsupports a to-be-processed object; a double-configured covering unit, which includes a first covering frame body that divides a processing chamber of the processing bench and a second covering framethat encloses the first covering frame body across a gap space; the dust collector mechanism, which includes an external gas feeding unit that penetrates through the first and second coverying frame bodies and feeds external gas into the processing chamber, and an exhaust unit which penetrates through the first and second coverying frame bodies and discharges the gas in the processing chamber; a constant-temperature air feeding port which is arranged on the second coverying frame and used for supplies constant-temperature air, which has been adjusted to positive pressure relative to the processing chamber and the exter