A radiation measurement apparatus comprising: a detecting section which comprises a plurality of detectors (34, 36, 38) provided to have directivity characteristics that differ from each other, and which detects radiation with the detectors (34, 36, 38); a calculating section adapted to calculate, based on a plurality of detection data obtained by the plurality of detectors (34, 36, 38) and for each energy interval (64, 66, 68, 70, 72) among a plurality of energy intervals (64, 66, 68, 70, 72), actual ratio information by determining a plurality of count ratios, which are a plurality of actual count ratios, by normalizing the plurality of individual counts of each detector (34, 36, 38) with a sum of the individual counts in the energy intervals and by form-ing actual ratio information as a combination or a sequence of the plurality of count ratios; a generating section adapted to generate, for each energy interval (64, 66, 68, 70, 72), a response function which provides theoretical ratio information which changes according to an incident direction; and a comparing section which compares a plurality of actual ratio information corresponding to the plurality of energy intervals (64, 66, 68, 70, 72) with a plurality of response functions corresponding to the plurality of energy intervals (64, 66, 68, 70, 72), and adapted to identify, when a matching relationship is determined between particular actual ratio information and particular theoretical ratio information, at least one of an incident direction and an energy interval (64, 66, 68, 70, 72) for radiation detected by the detecting section based on the matching relationship. a detecting section which comprises a plurality of detectors (34, 36, 38) provided to have directivity characteristics that differ from each other, and which detects radiation with the detectors (34, 36, 38); a calculating section adapted to calculate, based on a plurality of detection data obtained by the plurality of detectors (34, 36, 38) and for each energy interval (64, 66, 68, 70, 72) among a plurality of energy intervals (64, 66, 68, 70, 72), actual ratio information by determining a plurality of count ratios, which are a plurality of actual count ratios, by normalizing the plurality of individual counts of each detector (34, 36, 38) with a sum of the individual counts in the energy intervals and by form-ing actual ratio information as a combination or a sequence of the plurality of count ratios; a generating section adapted to generate, for each energy interval (64, 66, 68, 70, 72), a response function which provides theoretical ratio information which changes according to an incident direction; and a comparing section which compares a plurality of actual ratio information corresponding to the plurality of energy intervals (64, 66, 68, 70, 72) with a plurality of response functions corresponding to the plurality of energy intervals (64, 66, 68, 70, 72), and adapted to identify, when a matching relationship is determined between particular actual ratio information and particular theoretical ratio information, at least one of an incident direction and an energy interval (64, 66, 68, 70, 72) for radiation detected by the detecting section based on the matching relationship.