In this embodiment, for example, it can be set at 600??? C. equal to a film formation temperature. [0048] After that, the gate valve 39 is closed, and inert gas, such as an argon gas and the like is introduced from the gas introduction tube 38 to the reactive furnace 14, and the pressure thereof is raised to a film formation pressure. [0049] Then, when the temperature and the pressure in the react