A process for cleaning a chamber in a Chemical Vapor Deposition apparatus includes removing a polysilicon layer formed on the interior of the chamber after a doped polysilicon layer has been deposited on a wafer through Chemical Vapor Deposition, and depositing a doped polysilicon layer on the interior of the chamber. With such a process, enough doped ions can be absorbed by the interior of the chamber, and ions doped in a process of depositing a doped polysilicon layer on a surface of a wafer can be prevented from being absorbed on the inner walls of the chamber and the other components in the chamber, resulting in stable doped constituents and resistance value of the doped polysilicon layer deposited on the surface of the wafer.