PROBLEM TO BE SOLVED: To enable greening of a wall surface by keeping a wall surface of a building wet. SOLUTION: In this siding 1, a container 2 is detachably provided on a metallic base plate 11. The container 2 is made of synthetic resin or metal, and it is a box body, the top of which is opened, and which can be formed in an appropriate shape. A fixed part 22 of the container 2 is fitted fixedly in a slit 12 provided in the base plate 11, and freely detachable. A groove or a recessed part is formed on the back of the base plate 11 so that even when the wall surface has some projections and recesses to be uneven, the base plate can be firmly stuck to the wall surface. The pattern of the groove and the array of recesses can be made appropriately. A plurality of holes 21 are formed at the bottom of the container 2, and moisture in the interior of the container 2 is gradually discharged from the holes 21. The container is filled with soil and suitable plants are set in the soil, thereby greening the wall surface where the siding 1 is installed. COPYRIGHT: (C)2008,JPO&INPIT