PURPOSE: To prevent vibration at the back of a work even if cutting and grinding are executed while turning the work and to reduce generation of noise and increase the finishing accuracy by installing the captioned apparatus between the head stock and the feed dog of a lathe.

CONSTITUTION: A pair of holding levers 2 and 2' each having a contact part 4, 4' are installed oppositely on a base body in a swingable way urged by urging springs 13 and 13'. The holding lever 2 and a lever 11 on one side are connected to a solenoid 7, and further connected to each other through a link mechanism 8. As a pair of holding levers 2 and 2' are simultaneously hole and released, vibration at the back of a work can be prevented, even if a work 3 is revolved during the process of cutting and grinding, provided that the captioned apparatus is installed between the head stock and the feed dog of a lathe.