PURPOSE: To provide frames for attaching natural lighting windows correspondingly to the number of the attached natural lighting windows by mounting the frames for attaching a plurality of the natural lighting windows on wooden frames for the natural lighting windows and connecting the adjacent frames for attaching the natural lighting windows.

CONSTITUTION: A plurality of frames 2 for attaching natural lighting windows are mounted on rectangular wooden frames for the natural lighting windows provided on an opening part which is disposed on a roof and the water proof connecting pieces 2a of the frames 2 for the adjacent lighting windows are connected. An attaching sash 5 for attaching a natural lighting window 4 to a frame for attaching each natural lighting window is mounted. Thus, by connecting the frames 2 for attaching a plurality of the natural lighting windows, even when a plurality of natural lighting windows 4 are provided, the number of the natural lighting windows 4 can be met by connecting the frames 2 for attaching the natural lighting windows in accordance with the number of the lighting windows 4.