PURPOSE: To improve temperature observation effect, by a method wherein an object is taken a photograph by an infrared camera so as to detect positions and temperature values of a pluraity of designated points, and said positions and temperature values detected are displayed in one display at the same time.

CONSTITUTION: Based upon an infrared image signal applied from an infrared camera 1, temperature distribution of an object is dispayed on a monitor TV3. For example, when a switch 501 for setting designated points is turned ON, a designated points control part 52 transmits an address, which is to be stored in a position register 208 at a parallel blanking period of a TV image signal applied from an output timing generating part 210, to a storing part of positions of designated points 54 and a storing part of digits of designated points 55. Similarly, the designated points are set in the storing part of positions of designated points 54 and the storing part of digits of designated points 55, by operating switches 502W510.