To provide a pierce nut having a large seat area and large caulking strength, and firmly fixable to a metal panel.

In this pierce nut 1, a large diameter flange part 4 is formed at the lower end of a main screw cylindrical body 2, a pilot part 5 is formed at the lower surface center part of the flange part 4, and an annular outer wall 7 forming a seat face 8 in contact with the metal panel 11 is formed at the lower surface outer peripheral part. An annular groove 9 is formed between the pilot part 5 and the annular outer wall 7, and the end face 6 of the pilot part 5 is projected from the seat face 8. The outer diameter B of the pilot part 5 at the end face 6 is larger than the outer diameter A of main screw cylindrical body 2 at the lower end. Also, the outer peripheral surface of the pilot part 5 is tilted to an inner recess side of the axis of the nut, and a recessed/protruded part is formed on the outer peripheral surface.