To simplify interior finishing and exterior finishing by applying at least intermediate coating and finish coating among scratch coating, intermediate coating, and finish coating on the surface of a panel with a spray gun, and applying baking after the finish coating.

A white acrylic resin paint is applied to a metal sheet panel P as scratch coating, a lacquer ink is applied on the scratch coating as intermediate coating, and a finish coating paint is granularly applied on the intermediate coating by a spray gun to form a marble-like texture pattern 1. A rhombic pattern is stuck on the marble-like texture pattern 1, a paint containing pulp fibers is applied to the remaining portion, a texture pattern 2 of Japanese paper is formed, and a continuous pattern is displayed. A panel is formed similarly to a marble pillar or wall, and it can be manufactured at a very low cost.