To allow the manufacturing process of thermometers to be simple and rapid, and to improve the performance of thermometers by selecting combinations of the arrangement of resistances and capacitors.

The IC of the thermometer is provided with a combination of resistances and capacitors and a logic switch control system or a formulized compensation variable table. A preset target values of a software and a hardware are used in a calibration system, and the most suitable arranged combination of sets of the compensating resistances and capacitors is selected and written into a built-in or externally connected memory. The most suitable arranged combination of the compensating resistances and resistances is selected in a serial or parallel method and reserved using a fusing method in which the voltage and current are increased. Thereby, a system oscillating frequency and a voltage value of a power lack alarm signal are easily adjusted to the target values, and the oscillating frequency of a thermistor and its circuit are allowed to be in harmony with the oscillating frequency of an center resistance combined and its circuit. Thereby, such a known thermometer drawback that the manufacturing process is complexed because of requiring the adjustment of combination of the resistances and capacitors using a large amount of manpower can be solved.