Patent ID: 7241346

Claim:
A film-forming apparatus comprising: a plate which is to be exposed to process gas and has an embedded heater that generates heat by resistance heating; a terminal which is exposed at one surface of the plate and supplies power to the heater; a first seal surface provided on the plate, shaped like a ring and surrounding the terminal; a stem shaped like a hollow cylinder, surrounding the terminal and supporting the plate; a second seal surface shaped like a ring and extending along that end of the stem which supports the plate; a cover which closes an open end of the stem, which is opposite to the end which supports the plate; a conductor passing through the cover into the stem and connected to the terminal; a flow path provided in the cover and configured to supply inert gas into the stem; and a seal ring interposed between the first and second seal surfaces, said seal ring comprising an inner circumferential part and an outer circumferential part, said inner and outer circumferential parts being in contact with the first and second seal surfaces so that an unattached zone is defined all around between the inner and outer circumferential parts, wherein the seal ring has a cross section formed in an H-shape all around.