1 : A temperature detecting range identifying device comprising: a storing portion that stores location coordinates of a planned detecting range over which a thermopile array sensor is to detect temperatures, for each of a plurality of thermopile array sensors installed in a space for which a temperature distribution is to be detected; a detected temperature acquiring portion that acquires detected temperatures from each individual thermopile array sensor; a temperature change comparing portion that compares, for two thermopile array sensors, from among all of the thermopile array sensors, having planned detecting ranges that partially overlap each other, for each test location on a side of one selected thermopile array sensor, within an overlapping region, with each comparing location on a side of an other selected thermopile array sensor, within planned detecting region of the other thermopile array sensor, a change in detected temperatures over time, detected at the respective locations, to identify a best match location wherein a highest comparison result is obtained; a factor estimating portion that generates, for each test location, an equation expressing a relationship between the best match location for the test location and positional shift factors indicating a positional shift between a location coordinate indicating the test location and a location coordinate indicating the best match location, and establishes these equations as a system and solving using a least-squares method to estimate the positional shift factors; and a detecting range identifying portion that identifies an actual identifying range for the other thermopile array sensor by correcting the location coordinates of the planned detecting range for the other thermopile array sensor based on the positional shift factors.