Abstract: A method of manufacturing large thin wall ceramics board includes pulverizing and uniformly mixing, in dry content conversion, plasticity clay in an amount of 30-40% by weight, wollastonite having an aspect ratio of more than 10 in an amount of 20-50% by weight, and feldspar and talc in an amount of 10 50% by weight to form a mixture. The mixture is added with a solution having a 16-21% weight of the weight of this mixture. The solution has 10% by weight of a paraffin emulsion. The clay-like composition is extruded with a vacuum kneading machine to form a cylindrical shape. The extruded clay-like composition is made into dough board compact of desired thickness after being partially cut parallel to the cylinder. The dough board compact is heated to approximately 80 degrees Celsius with far infrared radiation.

Abstract: Large and thin ceramic plates of, particularly at least 30.times.30 cm in size and not greater than 20 mm especially not greater than 8 mm in thickness and having oriented crystals are produced by a method comprising drawing a green body from an extruder in a curved shape, cutting and spreading the green body in a plate form, rolling the plates in the same direction as that of drawing, subjecting the rolled plates to the treatment with far infrared rays or high-frequency heating before the plates contain a moisture reduced to less than 15% while the plates are transferred in the same direction as that of drawing, drying the plates thus treated while the plates are further transferred in the same direction, and then firing the plates in a kiln. The ceramic plates are large and thin but nevertheless easy to handle.