PURPOSE: To surely and accurately provide a recessed and projected pattern to a surface of an uncured ceramic planar material even if it has a large depth and to provide the recessed and projected pattern with a high productivity.

CONSTITUTION: A ceramic planar material 1 extruded into a planar form is received by a pallet 3. The pallet 3 is fed at a speed synchronous with an extruding speed. In the feeding process, a planar die 5 having a recessed and projected pattern on its surface is abutted on the surface of the ceramic planar material 1, and the planar die 5 is pressed down against the surface by rolls 6...6 from the rear surface thereof with gradually increasing linear pressure, whereby the recessed and projected pattern is provided to the surface of the ceramic planar material 1 and, simultaneously, a board thickness is adjusted. By using the planar die 5, a deep and sharp recessed and projected pattern with a high linearity is provided.