Figure 3 shows the heating characteristics in the ultrahigh-vacuum chamber of the thin film heater with MoSi2 film deposited on the outside of the alumina crucible, taking practical use into consideration. This thin film had high stability, and the heating temperature of this heater reached 1000 °C, with an electric power of approximately 190 W. At a low heating temperature, the pressure increased because of gas generated from the heater and then subsequently decreased with increasing temperature.