PURPOSE: To provide the building plate which has an excellent designing property and is inconspicuous if stained and to provide the multicolor coating method which can easily coat only a part of plane parts without making laborious operations, such as masking.

CONSTITUTION: Since the three points; groove parts 2, plane parts 3 and a part of the plane parts 3 of a base material 1 are selectively coated with three kinds of coating materials of the colors of the same system, the ruggedness of the base material 1 can be stressed by the selective coating of the groove parts 2 and the plane parts 3 and variation is provided in the plane parts 3 by the selective coating of the plane parts 3 and a part of the plane parts 3. The base material 1 formed with ruggedness on the surface is coated with the 1st coating material 5 over the entire surface thereof by a spray 4, is then coated with the 2nd coating material 7 over the entire part of the plane parts 3 by a roll coater 6 and is finally coated with the 3rd coating material 9 in a part of the plane parts 3 by a letterpress roll 8 and, therefore, only the parts in contact with a pattern plate 10 mounted to the letterpress roll 8 can be coated with the 3rd coating material 9.