A barrier film which has uniform thickness and excellent adhesiveness to the base material and superbly functions to protect a platinum film can be formed on the inner wall surface of a moisture-generating reactor at ease and at a low cost. The intrinsically conductive polymer salt and aluminum oxide coating that is formed resists corrosion and is resistant to de-doping during immersion in hot water. A memory in data communication with a processor stores a plurality of compensation parameters selected for use in correcting errors induced by the lens array. The inner wall surface and the ribs of the curved wall are coated with an antivibration material made of soft resin.