To provide a self-cutting undercut opening anchor that can form an undercut efficiently in a cylindrical storage hole.

A self-cutting undercut opening anchor has an anchor rod 2 provided with a head part 3 enlarged in an insert direction S, and a sleeve 5 arranged around the anchor rod 2. Opening pieces 7 separated from each other by a longitudinal slit are provided at a part, opposed to the head part 3, of the sleeve 5, and the sleeve 5 is axially moved on the head part 3 to push the opening pieces 7 open in a radial direction. The sleeve 5 is provided with at least one cutting edge 10, and an undercut is cut in the foundation by the rotation of the sleeve 5. The cutting edge 10 is provided at the front longitudinal edge 11 of the opening piece 7 from the rotating drection R view, and the cutting edge 10 is provided at least over a part of the axial length (1) of the opening piece 7.