To prevent intrusion of water from a joint part of an aluminium extruded shape to the inside of it.

A piece 3 to be fitted is provided on one side edge part of an aluminium extruded shape 2 to be formed in a constant sectional shape along the overall length in the longitudinal direction by aluminium extrusion molding, and an installation piece 5 having a fitting groove 4 free to store and receive the piece 3 to be fitted of the other aluminium extruded shape 2 adjacent to the other side edge part is provided. At the time of constituting a face by making a plural number of these aluminium extruded shapes 2 adjoin flush with each other, a waterproofing gasket 7 is compressively interposed between the installation piece 5 of the aluminium extruded shape 2 and the side edge part of the other aluminium extruded shape 2 adjacent to this installation piece 5, and a projected edge part 8 extending in a direction of the other adjacent aluminium extruded shape 2 is provided on the piece 3 to be fitted of the aluminium extruded shape 2. Additionally, a waterproofing packing 9 with which the projected edge part 8 is made pressure contact is provided on a groove bottom of the fitting groove 4 of the installation piece 5 of the other aluminium extruded shape 2.