To provide paneling light and hard to rust having excellent heat insulation property and strength.

The paneling 3 consists of two composite boards 7 arranged to face each other and a core material 8 made of resin and sandwiched and adhered between them. As a composite board 7, for example, a middle material 11 made of polyethylene resin or the like is sandwiched and adhered between a surface panel 9 and an inner panel 10 which are made from two aluminum panels or stainless steel panels. Made from resin sandwiched between two aluminum panels or two stainless steel panels, the composite boards 7 has excellent hardness and thermal insulation property. If the paneling 3 is used for a cargo box of a refrigerator truck or the like, temperature rise in a refrigerator can be restricted and electrical power consumption for cooling the refrigerator can be significantly cut off. Especially in the case that the paneling 3 is used for a door member, corrosion and rust due to penetration of water can be prevented when compared with a case that wood is used as a core material.