Embodiments of the present disclosure provide a plasma processing system, comprising: a transfer chamber, the transfer chamber including a plurality of sidewalls, each sidewall being connected with a plurality of process chambers; each process chamber including a base therein, the base including a central point; wherein at least two process chambers connected to a same sidewall form one process chamber group, wherein a first distance is provided between the central points of two bases in a first process chamber group, and a second distance is provided between the central points of two bases in a second process chamber group, the first distance being greater than the second distance; and the transfer chamber comprises a mechanical transfer device; a rotating pedestal includes two independently movable robot arms thereon, the two robot arms; and the two robot arms both include a plurality of rotating shafts and a plurality of rotating arms, wherein a remote rotating arm of each robot arm further includes an end effector for holding a substrate. The mechanical transfer device according to the present disclosure may simultaneously retrieve and place the substrate in the process chamber group with the first distance and the substrate in the process chamber group with the second distance.