摘要 |
A heat-treating apparatus includes a process tube accommodating an object to be heat-treated therein, and a plurality of independent heaters including at least three heaters arranged at both end portions and the central portion of a side wall of the process tube, so as to surround the process tube and, the heating temperatures of the individual heaters being freely adjustable. In this heat-treating apparatus, no direct heat transfer is caused between the heaters, so that the heating temperature of the heater at each end portion of the process tube can be adjusted to a high value, without entailing such an uneven temperature distribution as is caused in the case of a conventional heat-treating apparatus. Thus, uniform temperature distribution can be attained in an area covering the same range for the conventional apparatus, even though the heaters at both end portions are reduced in length.
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