To provide a calibration device for a device with a built-in sensor capable of acquiring precise calibration data, while simplifying a facility and reducing a burden for working.

A one-point observation data S3 of a product 10 is found, for example, based on an output value Sx of the product 10 acquired at an ambient temperature Tx. Characteristics in respective part circuits 1, 2 of the product 10 are observed preliminarily. A temperature calibration device 20 computes a composition sensitivity c of the product 10 based on the characteristics a, b, computes two-point estimation data S15, S175 serving as input and output characteristics of the product 10, based on the composition sensitivity c and the one-point observation data S3, and writes those into a calibration data storage memory of the product 10. The product 10 calibrates a detected output signal S, using the calibration data.