US Patent 7799719 Ceramic member and corrosion-resisting member

A ceramic member having a high density, small grain diameter, and excellent plasma resistance is provided. The ceramic member is constituted of a fine structure composed of fine grains, which is a ceramic member comprising an yttria as a main component and obtained through firing, wherein the ceramic member has an open porosity, as determined through a measurement by the Archimedes method, of less than 0.5%. By diminishing open voids, sites which is an origin of plasma erosion can be diminished. Thus, a ceramic member having excellent plasma resistance can be provided. By inhibiting abnormal grain growth to form a ceramic member constituted of stall grains, particle contamination by dusting can be reduced. Thus, plasma resistance and preventing particulate contamination can be improved.