PROBLEM TO BE SOLVED: To provide a device capable of obtaining a pulsating signal suitable for observation regardless of a unit used for measurement.SOLUTION: A subject information detection device 13 comprises: a subject information detection unit 32 provided with a casing part forming a cavity that is a space structure, which isolates a portion constituting an external ear of a subject from an outside space and is closed or substantially closed in a state of being fitted to the subject, and a sensor provided in the casing part for detecting pulsating signals of a blood vessel in a portion constituting the external ear as pressure information propagated inside the cavity due to the pulsating signals； and a gain switch part 95 for detecting saturation of the signals output from the subject information detection unit, and attenuating the signals when the saturation is detected.SELECTED DRAWING: Figure 1
