Gas processing apparatus and gas processing method

A gas processing apparatus comprising:

• a processing container for housing a substrate to be processed;
• a mount table, arranged in the processing container so as to define a horizontal plane, constructed so that the substrate can be mounted thereon;
• a processing-gas discharging mechanism arranged above the mount table to discharge a processing gas into the processing container;
• wherein the processing-gas discharging mechanism comprises a shower head which includes a shower base attached to the processing container, and a shower plate fixed to the shower base at a periphery thereof and arranged to oppose the substrate mounted on the mount table,
• wherein a plurality of gas discharging holes are formed in the shower plate to discharge the process gas toward the substrate mounted on the mount table,
• wherein a coolant passage extends between the gas discharging holes through the shower plate, and
• wherein a heat-insulating gap is formed between opposing surfaces of the shower base and the shower head to avoid direct metal-to-metal contact therebetween.