The present invention discloses a drill bit 100 comprising a plurality of cutting blade portions 131 for gradually cutting the surface and the inner wall of bones, a plurality of channels 132 for temporarily storing bone chips produced to be agglomerated by the cut bones and for discharging outside the chips, and a working portion 130 having a blocking portion for blocking further approach of the drill bit 100 after it approaches in the bones as much as the length of the plurality of cutting blade portions 131, wherein the plurality of cutting blade portions 131 and the plurality of channels 132 are alternatively formed to have equal interval in circumferential direction, and at least portion of the bone chips produced to be agglomerated in the plurality of channels 132 is located before the plurality of cutting blades 131.
