Patent ID: 8877002

Claim:
An internal member of a plasma processing vessel, comprising: a base material, wherein the base material comprises at least one of stainless steel, Al, Al alloy, W, W alloy, Ti, Ti alloy, Mo, Mo alloy, carbon, oxide or non-oxide based sintered ceramic body, and carbonaceous material; and a film formed on a surface of the base material, the film having pores therein, wherein the film includes a first ceramic layer and a second ceramic layer, the second ceramic layer formed in contact with the base material, wherein the first and second ceramic layers include at least one kind of element selected from the group consisting of B, Mg, Al, Si, Ca, Cr, Y, Zr, Ta, Ce and Nd, and at least parts of the pores in the film is sealed by a sol-gel method using Y 2 O 3 to form a sealing-treated portion, wherein the sealing treated portion is formed in a lower portion of the second ceramic layer to make a contact with the base material, and wherein the sealing-treated portion is not formed in an upper portion of the film to suppress surface degradation of the film.