PURPOSE: To carry out efficient and economical grinding of a drill tip by employing three independent servo motors to effect the drill rotation, the drill lift and the drill field in a drill grinding device to grind the drill tip of a twisted blade.

CONSTITUTION: A grinding wheel 9 is supported on a housing 5 movably in 12 directions by an actuator 14, and a drill 3 to be ground is held by a drill holder to be chucked to a work head 13. The drill 3 is rotated by a drill motor, and vertically moved in 21 directions by the action of a drill feed mechanism including a lift motor integrated with the work head 13, and oscillated around the axis 27 by the action of the drill feed mechanism including a feed motor. The lift motor and the feed motor are operated by the relationship regulated with respect to the rotation of a drill 3 in the work head 13, and the cutting cycle to each cutting edge of the drill 3 is completed by the rotation of the drill 3.