PURPOSE: To simplify the construction of an outer lighting frame by a method in which lighting building plates having watertightly lighting plates on the small holes of its bottom main plate are placed in parallel through receiver metals on a structure, and the connecting parts of the adjacent building plates are connected.

CONSTITUTION: Connecting parts 3 are provided to the upper ends of sides 2 above both sides of a bottom main plate 1, and a lighting plate 4 is provided on many small holes 1b of the plate 1 in such a way as to cover them watertightly to form a building plate A for lighting. The plates A are placed in parallel on receiver metals 9 fixed at an interval to the upside of a structure 8, and the connecting parts 3 of the adjacent plates A are connected. Adequate light can thus be uniformly taken into rooms and an outer lighting frame of good rain proofness can also be simply constructed.