To make an eaves body watertight, firm and stable, even when the eaves body is formed by joint connection performed by attaching eaves plates while bringing them close to one another.

An overlap portion 29a of an L-shaped fixing bracket 29 is superposed on the base end of the eaves plate 3 having an insertion attachment portion 19 provided on one side surface and having a retainer portion 20 provided on the other side surface; a first bolt 27 is inserted through both of them; its head 27a is engaged with a locking groove 10 which is formed in a horizontal piece 2b of a mounting member 2; a second bolt 32 is inserted through a rising piece 29b of the L-shaped fixing bracket 29; its head 32a is engaged with a locking groove 7 which is formed in a vertical piece 2a of the mounting member 2; first and second nuts 34 and 35 are temporarily tightened to the first and second bolts 27 and 32, respectively; and the operation of attaching eaves plates 3 while bringing them close to one another is performed by being guided by the locking grooves 10 and 7. When the eaves plates 3 are joined together by fitting the retainer portion 20 and the insertion attachment portion 19 together, the operation of finally tightening the first and second nuts 34 and 35 is repeated to easily and rapidly constitute the watertight firm eaves for the building.