The present invention obtains a reliable estimation result by preventing an incorrect estimation result from being output as a correct estimation result when a subject's measurement state changes due to the subject's movement. A biological state estimating device 20 fetches, at a regular acquisition cycle, facial image data of a driver output from a camera 40 and fetches, at the acquisition cycle, electrocardiographic data transmitted from a wearable terminal 50. First to third drowsiness estimating units 213 to 215 detect, from the facial image data, features indicating vestibulo-ocular reflexes (VOR), features indicating blinking movements of the eyes or closing and opening movements of the eyelids, and features conveying the driver's facial expressions, and estimate a user's drowsiness on the basis of these features. A fourth drowsiness estimating unit 216 detects features associated with human autonomic nervous activity from the electrocardiographic data and estimates the user's drowsiness on the basis of these features.
BIOLOGICAL STATE ESTIMATING DEVICE, METHOD, AND PROGRAM