An information detecting device detects information from a target. The information detecting device includes processing circuitry. The processing circuitry is configured to perform a first information acquisition operation of acquiring first information from a target criterion, a second information acquisition operation of acquiring second information from the target, and an information conversion operation of converting the second information acquired by the second information acquisition operation, into third information, with the first information acquired by the first information acquisition operation, the third information having a dimension different from respective dimensions of the first information and the second information; and perform control such that an information-acquisition condition in the first information acquisition operation is identical to an information-acquisition condition in the second information acquisition operation.