PURPOSE: To secure the stable set state by a method wherein a hollow bore is formed through the pin to be opened at its upper end and a plurality of small holes in communication with the hollow bore for leaking out a hardener are dispersedly formed in the peripheral wall of the pin.

CONSTITUTION: The surveying pin 1 is formed at its tip end with a sharpened point 5 for allowing the pin to be easily put through the ground 4 and with winglike projections 6 radially extending in the outward direction so as to permit the pin to be put through just in the vertical direction. The pin 1 also includes a rugged pant 9 formed on its shaft. A hollow bore 10 is formed through the pin 1 to be in communication with an opening 2 formed at the upper end of the pin 1. A plurality of small holes 11 in communication with the hollow hole 10 are dispersedly formed in the peripheral wall of the pin, so that a ground hardener poured into the hollow bore 10 is leaked out into the ground at the circumstance of the pin. An indication plate 3 is attached to the upper end of the pin 1.