PURPOSE: To minimize the labor at a construction site by mounting on a reinforcement core a frame outer surface member comprising a metallic net and an interwoven net formed into a combined plate.

CONSTITUTION: A metallic net 1 and an interwoven net 2 are stacked one atop the other so that a frame outer surface member 3 is formed the outer surface of which is the metallic net 1 and the inner surface of which is the interwoven net 2. The frame outer surface member 3 is mounted on the outside of a reinforcement core comprising horizontal reinforcement 5, 6 and vertical reinforcement 7, so as to form a frame body 10 for concrete casting. The frame body 10 is conveyed to a site of concrete placing and when concrete is placed the metallic net located on the inner surface of the frame body bites into the placed concrete so that a firm construction is formed. Therefore, the frame body can be assembled by a simple assembling work.