PURPOSE: To provide a double-side machining tool capable of performing double- side machining with one index table.

CONSTITUTION: Five workpiece holding parts 23, 23A, 23B, 23C, 23D are disposed at a turnable index table 21. A carry-in clamp 26 for carrying a workpiece 24 in is provided in correspondence with the workpiece holding part 23, and a carry-out clamp 29 is provided in correspondence with the workpiece holding part 23C. A polishing device 27 is provided in correspondence with the workpiece holding part 23A provided in the feed direction Z of the workpiece holding part 23, and a workpiece reversing device 30 is provided in a workpiece reversing position disposed in the feed direction Z of the workpiece holding part 23A. The surface 24A can be thereby machined in the first round of the workpiece 24, and the back face 24b can be machined in the second round.