To easily and quickly replace only a head part at good fitting accuracy without replacing the whole shaft member when the head part in the shaft member for formation is worn.

A piercing pin 1 in a forming apparatus for piercing is constituted of a bar-like piercing pin body 11, a head body 12 and a connecting pin 13. An engaging recess 11a is formed at the distal end part of the piercing pin body 11 and also, an inserting part 12a for inserting into the engaging recess 11a and an abutting face part 12b for abutting on the distal end face 11b of the piercing pin body 11 are formed at the rear part of the head body 12, Whereas, at the engaging recess 11a of the piercing pin body 11 and the inserting part 12a of the head body 12 are formed with inserting holes 11c and 12c for connecting pin and communicating over the engaging recess 11a and the engaging part in a direction perpendicular to the axial direction of the piercing body 1, and then, the connecting pin 13 is engaged in an ejectable manner into these inserting holes 11c and 12c, so that the piercing pin body 11 and the head body 12 are connected detachably and attachably.