To provide a building frame for constructing a building, the frame being stronger than reinforced concrete, and being able to be relatively easily assembled at a construction site, without skills, and within a short time. [Solution] Provided are a building frame and the like, the building frame being characterized by comprising: U-shaped parts that are arranged left and right so as to sandwich a center space in a cross-sectional view; and a connection part that connects top portions, on the center side, of the left and right U-shaped parts so as to form a reverse U-shaped part, wherein the longitudinal edges, on the far side from the center, of the U-shaped parts arranged left and right in the cross-sectional view are shorter than the longitudinal edges, on the center side, connected by the connection part.