An object of the present invention is to increase the dimensional accuracy of a structure including a plurality of rectangular pipes. A structure (6) includes a plurality of rectangular pipes (60) joined together. The plurality of rectangular pipes (60) include a first rectangular pipe (60a) and a second rectangular pipe (60b) joined by welding. Two or three of four sides that constitute an end face (62) of the first rectangular pipe (60a) are joint sides (62a) welded to a side face (63) of the second rectangular pipe (60b), whereas the rest of the four sides is a non-joint side (62b) separated from the side face (63) of the second rectangular pipe (60b) by a gap.