PURPOSE: To bond a plastic sheet easily and securely to a curved surface wooden material by pulling inwardly both ends of a cloth covering over a curved surface and the cut end surface through a clamping tool.

CONSTITUTION: A vinyl chloride sheet 2 is brought into contact with a curved surface 1a and a cut end surface 1b of a curved surface wooden material 1 coated with a bonding agent, and foams generated between the curved surface 1a,the cut end surface 1b and the vinyl chloride sheet 2 are defoamed. Next, an inner section support 4 for preventing deformation is disposed, and a cloth 5 is applied over the wooden material 1 from over the sheet 2, and then both ends of the cloth 5 are pulled inwardly with a clamping tool 6, and the sheet 2 is pressure bonded. In order to prevent dirt, a polyester film 10 and a cushion material 11 such as a rubber sheet or the like are inserted between the sheet 2 and the cloth 5, and also a polyester film 12 is inserted between the cushion material 11 and the cloth 5 for the purpose of sliding the cloth 5 better. Bonding the plastic sheet on the curved surface and the cut end surface can be carried out efficiently by said process.