PURPOSE: To perform drill work in a stable condition by clamping a work piece in the vicinity of a quill.

CONSTITUTION: A cover 14 is provided which is covering an opening part 3a formed on a head 3. A lock plate 15 is inserted in the slit 14a and hole 3b of the cover 14 to be energized in a fixed direction by a spring 16. A shaft 17 is penetrated in the hole 15a of a lock plate 15. A sleeve 18 is rotatably provided on the tip side outer peripheral part of the shaft 17, and is retained at a given rotation position by a spring 19. A material presser member 20 is provided on the tip part of the shaft 17 rotation-regulatedly and also movably in an axis direction. A cam surface is formed on an abutting surface thereon the material pressor member 20 and the sleeve 18 abut each other.