PURPOSE: To obtain a shell structure which is excellent in the structural stability and makes it possible to reduce the constructtion cost, by mutually connecting frames of frame units stabilized in the structure to each other.

CONSTITUTION: Frame members 2 are assembled to form a right dodecagon to constitute the peripheral frames and tensile members 3 are spread around at the inside of peripheral frames as the inner members to form a structurally stable frame unit. A number of frame units 1 are arranged on the curved face of the shell and the frame units are closely connected to one another or in a closely contacted state. The surface members of the roof may be fitted later by using the frame units as skeletons or a part thereof may be attached to the frame units 1 in advance. On constructing, a plurality of frame units 1 are assembled in the state that they have been mutually bent or folded in advance and can be connected and fixed while spreading them on the shell- curved face.