To manufacture almost all plane and solid structures with commercial fittings and steel scaffolding pipes and to considerably enlarge the use of the commercial fittings and steel scaffolding pipes by connecting the steel scaffolding pipes with various kinds of structural parts manufactured using a pipe material of the same outer diameter and the same material as the steel scaffolding pipes by the commercial joint fittings to assemble them, disassembling them on the occasion of transportation to transport them efficiently, and easily manufacturing a structure of optional shape without a protruding part at a construction site.

An L-shaped structural part 21, a T-shaped structural part, a rectangular trilateral structural part, a cruciform structural part, a rectangular hexalateral structural part, a T-shaped joint fitting, a cruciform joint fitting and a rectangular tetralateral joint fitting are constituted using pipe material of the same outer diameter and the same material as a scaffolding pipe made of steel. These structural parts, steel scaffolding pipes and commercial joint fittings 23 are suitably combined to manufacture a structure body 24 of optional shape.