A greenhouse comprising two structures (1, 1) joined to each other. Each of the structures comprises a rectangular frame body (11) disposed horizontally, a rectangular main beam (12) vertically disposed on the frame body (11), and a principal rafter member (13) supporting the main beam (12). The greenhouse is characterized in that an interval between column members (2) disposed indoors in the lateral direction and an interval in the depth direction are set approximately equal to each other by supporting, on the column members (2), four corners of a joined body set so that the ratio of the lengths of its two sides crossing perpendicularly to each other is approximately 1:1 and supporting both ends of the main beams (12) of the structures (1, 1) on a beam member (3) installed across the column members (2) through the frame bodies (11).
