PURPOSE: To make a rattan material easily bendable to cope with the shaped curve of both of an incurved edge and an outcurved edge of a different material without heating, by forming a slot along a longitudinal direction of the material in a direction of a central part from one end of the rattan material having an almost circular sectional shape.

CONSTITUTION: A rattan material 1a comprising a slot 2 is bent to form an incurved edge. Another piece 1b is bent to form an outcurved edge. These curved lines can be easily formed manually. A mirror frame B which is separately prepared and of which a surface is decorated by a decorative cloth, has a horizontal lower end and a semi-circularly curved upper part, the slot 2 of the rattan material 1a which is bent in advance, is fitted along the shaped curve of the mirror frame B, and the ends of the rattan material 1a are fitted to the holes 4, 4 of the straight rattan material 3 mounted on a bottom side, and fixed by an adhesive agent. Then the slot 2 of an outer peripheral edge of the rattan material 1b of which the slot 2 is bent as the outcurved edge is fitted and adhered along an inner periphery excluding the bottom side of the mirror frame B. Whereby the technical experience is not so much required, the working is simplified and the working efficiency can be improved.