| 摘要 |
PROBLEM TO BE SOLVED: To reduce the possibility of generation of waste electric power in a heater.SOLUTION: A heater 10 includes: a ceramic body 1 having a cylindrical portion 11 and a lid portion 12 covering an opening 13 on one end side of the cylindrical portion 11; a heating resistor 2 embedded in the ceramic body 1; and a metallic cylinder 3 into which at least one end side of the ceramic body 1 is inserted. The surface of the lid portion 12 is recessed toward the opening 13 side. Since the surface of the lid portion 12 is recessed toward the opening 13 side, this structure prevents a recessed portion of the surface of the lid portion 12 from coming into contact with outside, so as to inhibit heat from escaping from the surface of the lid portion 12 to outside. Thus, generation of heat that escapes without contributing to heating an object to be heated can be suppressed. As a result, the possibility of generation of waste electric power in the heater 10 can be reduced. |
