Screw fixing mechanism employing fixed manner by a stopper not, higher by about a stroke section at a apparatus for correcting the stroke error often the signals with semiconductor manufacturing equipment provided to allow a great quantity of regulating stroke floating bar of, predetermined stroke at a specific interval of the sets a restriction regulates the operation of the protrusion (52) having floating shuttle bar (50) and a, said control protuberances (52) on both sides of control protuberances terminal (52) having floating shuttle bar (50) and a, said control protuberances (52) on both sides of control protuberances terminal (52) between the stopper depth is different according (60) and a, the stopper (60) the base part (65) having fixing block (62) and fixing block (62) is formed a female threaded part and female part has at screw stopper bolt (64) and a, the stopper bolt (64) one side of stopper bolt (64) is engaged, and a lock nut (66) regulating a stroke fabric comprised of the composed purpose : said stopper bolt (64) is threadedly connected to the contact portions (14) and a central to operational hole and a through-hole (92) value of branches a the stop block (12) and, is the stop block (12) of said operational hole and a through-hole (92) passing through the impact absorption member (72) structure can be applied for characterized in that a, floating shuttle bar of regulatory are prevented by on the stop block to even for applying impacts is continuously brought into contact, lock nut-end bolt stopper of the stopper of the stop block said state or collar collar state-end bolt, original setting is real estate can be conserved as the environment, ensures accurate stroke the client computer.. Therefore, higher by about the [...] those multiple cells of semiconductor manufacturing of and throughput productivity. to be fixed.