To solve problems caused by use of a solvent such as a danger of fire, a fear on health of an operator due to inhalation of a solvent vapor, a loss of an adhesive in spray application and a necessity of a wide plant space for a long process by required by a drying line in a conventional method for bonding a decorative plate on a core material having a horizontal surface and a curved end surface wherein a solvent base rubber based adhesive is applied to a front surface of the core material and a rear surface of the decorative laminate, dried, sent into a postforming machine after pressing the horizontal surface to a rear surface part contacting with the horizontal surface of the decorative laminate and processed by postforming to be bonded.

A water base honeymoon type adhesive is applied to a front surface (a horizontal surface and an end surface) and a rear surface of the decorative laminate. After pressing the front surface of the core material and the decorative laminate by piling up, the end part of the decorative laminate is heated, and by bonding to the end surface during bend processing, the conventional problems are solved.