A processing room includes a processing chamber, a discharge chamber, a sealing member, a blocking member, and a reclaiming member. The discharge chamber includes a main body communicating with the processing chamber, and a receiving portion and a discharge portion communicating with the main body. The receiving portion is aligned to the discharge portion. The sealing member includes a sealing portion and a sealing valve mounted on the sealing portion. The sealing portion is partially and moveably received in the receiving portion and resists against a sidewall of the receiving portion. The blocking member is detachably mounted on an end of the discharge portion and seals the discharge portion. The reclaiming member is partially received in the main body.