To easily perform polishing even if a drill is short by thinning a drill chuck for drill polishing as far as possible.

A drill chuck 1 for drill polishing is constituted of four chuck claws 2 faced to one another so as to chucking a lead part 6 of a blade part of a drill 5 to be polished, a claw sliding cylinder 3 in which the chuck claws 2 are to be mounted on a claw sliding part 4 having the conical inner surface so as to be raised, lowered and slid, a claw holder 10 to be approached to the upper surfaces of the chuck claws 2, having the side peripheral part to be fitted to the upper peripheral parts of the chuck claws 2 so as to be turned, and provided with a drill inserting hole 9 exclusively used for drill polishing in the center part, and a chuck outer cylinder 7 in which the claw sliding cylinder 3 is fixed and the outer periphery of the claw holder 10 is screwed to the upper periphery of it so as to be turned. The drill inserted among the chuck claws 2 and to be polished is detachably fixed by the chuck claws 2 by turning the claw holder 10. Therefore, a thin drill chuck having the thickness in the range of 30 to 35 mm can be performed.