A gas introducing unit 32 configured to introduce a processing gas into the processing container 4 is provided at a lower portion of the manifold 10. The gas introducing unit 32 includes a gas nozzle 34 provided to air-tightly penetrate the manifold 10. Although FIG. 1 illustrates a case where one gas introducing unit 32 is provided, a plurality of gas introducing units 32 may be provided according to, for example, the number of gas types to be used. A flow rate of the gas introduced from the gas nozzle 34 to the processing container 4 is controlled by a flow rate control mechanism (not illustrated).

A gas outlet 36 is provided in the upper portion of the manifold 10. An exhaust system 38 is connected to the gas outlet 36. The exhaust system 38 includes an exhaust passage 40 connected to the gas outlet 36, and a pressure regulating valve 42 and a vacuum pump 44 which are interposed in the middle of the exhaust passage 40. By the exhaust system 38, it is possible to exhaust the processing container 4 while adjusting the pressure therein.

Around the processing container 4, a heater 48 configured to heat wafers W is provided to surround the processing container 4. The heater 48 includes a heat insulating member 50, a protective cover 51, a heater element 52, and a holding member 53.