To develop a tool perforating a bolt hole, accurately passing through the center, in a pipe wall of a metal pipe becoming a foundation pile, or having a central angle accurately equally divided in a plan view and capable of easily perforating a plurality of bolt holes.

An engagement fitting 15 for a connection bolt hole perforation tool of the foundation pile is provided on an outer surface of an annular body 10 detachably fixed on an outer periphery of the foundation pile 1 made of metal such as casting iron and steel iron in a penetration direction perpendicular to a central axis. The perforation tool 14 for connection bolt hole is detachably mounted to the fitting 15 while directing the perforation axis to a radial direction of the foundation pile made of metal.