A chemical mechanical polishing (CMP) chamber is disclosed. The CMP chamber includes a chamber body, a door mounted on the chamber body and a chamber substructure being one selected from a group consisting of a moisture separator separating a moisture generated in the CMP chamber, a supplementary exhaust port, a transparent window mounted on the door, a sampling port mounted on the door, a sealing material including a metal frame, an o-ring for sealing the door and a combination thereof.