To prevent damages to protective members covering plasma-exposure portions of a plasma-treating apparatus, and reduce the dust generation by making at least a plasma-exposure portion of the protective members of SiC, except plasma electrode parts.

In a plasma-treating apparatus other portions than plasma electrodes E1, E2 and portions to be exposed to a corrosive etching gas G are covered with a protective member D shown by, e.g. 'depo-sheet' which has an SiC-made portion to be exposed plasma or a etching gas G. A SiC material for the member D may be, e.g. a sintered SiC, C reacted with Si and sintered, SiC converted from C, or chemically vapor-deposited or physically vapor-phase deposited SiC and an SiC hardly containing metal impurities is preferable.