PURPOSE: To erect a column very precisely in a determined position without requiring many hands.

CONSTITUTION: A plurality of base plates 12 having anchor bolts 14 fixed thereto are mounted on a connecting member in such a manner as to be attachable and removable. The connecting member is disposed on a determined surface with the anchor bolts 14 and the base plates 12 turned downward. A concrete 17 is then placed. After the concrete 17 is hardened, the connecting member is removed from the base plate 12. A column 24 is fixed in a determined position on a support member 21. Since the column 24 is not connected to the anchor bolts 14, the column 24 can be easily and very precisely positioned regardless of the dislocation of the anchor bolts 14 at the time of placing the concrete 17.