PURPOSE: To improve the appearance of worked surfaces and to enhance the durability thereof by arranging 1stW3rd coaters successively, thereby efficiently coating the plate work.

CONSTITUTION: The work carried in by a 1st carrying conveyor 4 is subjected to primer coating by the 1st coater 5 and is then dried by the 1st dryer 7 while the work is transferred. After this work is cooled by a 1st cooler 8, the work is transferred through 2nd carrying conveyor 9 to the 2nd coater 10. The work surface is subjected to color painting by the 2nd coater (roll coater) 10. The work is thereafter carried through a 3rd carrying conveyor 11 to the 2nd dryer 12 where the work is dried. The dried work is carried via a 2nd cooler 6 and a 4th carrying conveyor 13 into the 3rd coater 14. The work surface is subjected to clear painting by the 3rd coater 14, by which the durability of the worked surface is enhanced and the surface is smoothed to prevent sticking of dust, etc. Further the work is dried and is stacked by a stacking device 17.