PURPOSE: To provide quick, constant and sufficient chucking of a tool without use of machine tool by furnishing the second body, to which the chuck body is fixed, and the first body to which an arm to restrict rotation of a chuck clamper is fixed.

CONSTITUTION: The second body 2 rotates concentrically with the first body while holding its relative position therewith. A rotation limiter 3 is fixed to the second body 2 and restricts the chuck body so that it does not rotate relative to the second body 2. An arm 7 is installed in such a way as not to rotate relative to the first body 1, and inserted in a hole for fastening the chuck clamper 5 to restrict its rotation, and is supported by the first arm holder 6. The second arm holder 8 is fixed to first body 1 and capable of moving vertically without causing rotation of the first arm holder 6. A drive motor 13 is installed on the first body 1 and rotates the second body 2 relative to the first body 1 through a power transmission gear.