PURPOSE: To prevent worker dropping accident and to facilitate the reinforcement bar arrangement into a through-hole by surroundingly arranging a concrete mold releasing member at required positions on the construction site of a concrete structure.

CONSTITUTION: An earth retaining wall 15 is constructed at the planned spot of an underground building, and a temporary member 4 is driven in, and a working platform 17 is installed to excavate an underground. Next pipe fixing tools 6, 6... are fixed to forms 5 near the member 4, and pipes 2, 2... connected in series through a connecting member 3 are engaged with the pipe fixing tools 6, 6... to surround the member 4 for composing a concrete mold releasing member 1. Next reinforcements 18, 18... are insertedly attached in the gaps 20, 20... of the pipes 2, 2..., and bent upward, and concrete is deposited in the gaps 20, 20..., and after the concrete hardens, the members 1, 4 are removed to return the reinforcements 18, 18... to their original positions for back-filling the concrete into a through hole. Thus the member 1 is surroundingly arranged around the member 4 to prevent worker dropping accident and to facilitate the reinforcement bar arrangement into the through-hole.