PURPOSE: To prevent crack generation of a coating film, in applying an embossed pattern to a colored zinc plated steel plate, by a method wherein an embossing roll is provided to an outlet side of a baking furnace of a painting line and, during the time while the coating film of the baked steel plate is cured and remaining heat with a predetermined temp. stays in the steel plate, roll processing is carried out.
CONSTITUTION: After a steel plate 4 is taken out from a baking furnace 1, it is cooled in a cooling apparatus 2 at first and, after cooling, emboss processing is applied thereto by an embossing rol 3. In this case, the cooling by the cooling apparatus 2 is carried out in such a degree that a coating film is cured while remaining heat stays in the steel plate 4 and the temp. of the steel plate during emboss processing is adjusted to 30W70°C, pref., 40W60°C. Since the relationship of the cooling degree and the temp. during emboss processing is changed by a line speed, a plate thickness, a distance between the cooling apparatus 2 and the embossing roll 3, ambient temp. or the like, the cooling capacity of the cooling apparatus is allowed to be capable of being adjusted so as to set the temp. during emboss processing at a predetermined temp.