To provide a burring device by which all of the inner peripheral surface and the outer peripheral surface of a tubular projecting part are accurately formed.

This burring device is provided with: a burring die having a punch opening part on a placing surface of a material to be worked; a punch for forming the tubular projecting part on the material to be worked by forcing the material to be worked placed on the placing surface of the burring die into the punch opening part; a forming die having a forming opening part into which the tubular projecting part is inserted; a top supporting body which is situated in the forming opening part of the forming die and has opposing portions to the top surface and the inner peripheral surface of the tubular projecting part and a bottom supporting body which is relatively moved to the top supporting body in the attaching and detaching direction, imparts compressive load in the axial direction to the tubular projecting part between itself and the top supporting body by being brought into contact with the tubular projecting part from the opposite side of the nose supporting body and, with which the outer peripheral surface and the nose surface of the tubular projecting part are widened toward the inner peripheral surface of the forming opening part of the forming die while deforming the top part of the tubular projecting part by crushing.