To eliminate possibility to cause flaw on a polishing surface by providing a stationary fiber fixing part above a revolving polishing machine interlocking with a driving system arranged below.

A jig/fiber fixing bar 6 is projectingly fixed upward vertically to a casing 2, a cord fixing jig 7 is provided on a horizontally extended bar from the fixing bar 6, and fiber cords 8 are fixed to the fixing jig 7. The fiber cords 8 are bundled above the cord fixing jig 7, and in the lower parts, fibers 9 are exposed from the fiber cords 8. The projecting length L1 of the fiber 9 is set longer than the interval L2 from the cord fixing jig 7 up to a revolving polishing machine 4, and the revolving polishing machine 4 is revolved against the cord fixing jig 7 in the condition of bending the fiber 9. Thereby, possibility to cause flaw on the polishing surface is eliminated.