FIGS. 16A and 16B are views illustrating temperature reproducibility of the second heat treatment by the heat treatment apparatus having the first partitions 70 and 72 and the second partition 80. FIG. 16A is a graph which illustrates a change over time in the measured temperature in the area CB in the space S, and time is illustrated on the horizontal axis, and temperature [□] is illustrated on the vertical axis. FIG. 16B is a graph which illustrates a change over each run in the measured temperature at time tm2 in FIG. 16A, and the number of runs is illustrated on the horizontal axis, and temperature [□] at time tm2 is illustrated on the vertical axis. Further, a plurality of solid lines in FIG. 16A illustrate the result for each run.

As illustrated in FIGS. 16A and 16B, when the second heat treatment is performed using the heat treatment apparatus having the first partitions 70 and 72 and the second partition 80, it can be seen that the temperature fluctuation hardly occurs at each run, in all steps.

From the above results, it can be said that the temperature reproducibility at the second heat treatment accompanied by a change in temperature may be improved by providing the first partitions 70 and 72 in the space S. Further, it can be said that the temperature reproducibility at the second heat treatment accompanied by a change in temperature may be improved by providing the second partition 80 in the space S in addition to the first partitions 70 and 72.