Abstract: [Problem] To provide a processing device for uniformly grinding wafers held by a plurality of chucks, and a method for setting the processing device. [Solution] A processing device 1 includes a coarse grinding means 5 and a fine grinding means 6 that are provided in a column 4 straddling over a holding means 2. The holding means 2 includes: an index table 21; chucks 22 concentrically disposed about a rotation shaft 2a; a first movable support unit 24 disposed on the outer peripheral side of the chuck 22 in the radial direction of the index table; and a first fixed support unit 25 disposed on the inner peripheral side of the chuck 22 in the radial direction of the index table. The first movable support unit 24 is interposed between the index table 21 and the chuck 22, and can be freely expanded and contracted in a vertical direction.