According to one embodiments, a calibration detecting apparatus includes a generator, a setting unit, an acquisition unit, and a calculator. The generator generates location data indicating a group including a pair of two positions arranged respectively in two spaces. The setting unit sets an irradiation arrangement so that an irradiating device performs laser irradiation on a region including an end position of the end effector. The acquisition unit acquires observation data indicating whether or not the end effector is observed. The calculator calculates a change in an installed state of the irradiating device based on the observation data.