There is provided a structure which can reduce the lifting workload and the building workload at a high place. A structure 1 of the invention includes a rectangular frame 11 arranged horizontally, a rectangular main beam 12 arranged vertically on the frame 11, and a principal rafter 13 supporting the main beam 12 and can be built on the ground. The structure 1 is used as a greenhouse roof frame. The lifting workload and the building workload for building a greenhouse roof frame, a framework of the entire greenhouse and a greenhouse, can be greatly reduced as compared with those of the prior art.