A physiological state evaluation apparatus configured to partly enter into contact with an external auditory pore when mounted in a subject's auricle, the physiological state evaluation apparatus comprising: a bone conduction sound collection unit configured to collect, as an acoustic signal, a sound of vibrations generated from a larynx and a pharynx of the subject via a cartilage region of the external auditory pore of the subject; a blood condition measuring unit configured to optically detect a pulsatory motion of blood circulating through blood vessels of the subject and measures a pulse rate and blood oxygen saturation, respectively, on the basis of a change in optical intensity caused by the pulsatory motion; a biological signal detection unit that includes a pair of conductive electrodes for detecting electric potentials of right and left external auditory pore surfaces, respectively, of the subject and is configured to detect brain waves and eye movements of the subject; a respiratory condition detection unit configured to detect, as a respiratory condition, sound quality, the number of times, a tidal volume, and a rhythm of breaths of the subject on the basis of the acoustic signal by the bone conduction sound collection unit ; a sleep state evaluation unit configured to evaluate a health condition of the subject while sleeping on the basis of the respiratory condition detected by the respiratory condition detection unit, the pulse rate and the blood oxygen saturation measured by the blood condition measuring unit , and the brain waves and the eye movements detected by the biological signal detection unit ; and a body temperature detection unit configured to detect a tympanic membrane temperature of the subject according to an infrared ray system, wherein the sleep state evaluation unit is configured to evaluate the subject's health condition while sleeping on the basis of synchronization timing between the pulse rate measured by the blood condition measuring unit and the tympanic membrane temperature detected by the body temperature detection unit . a bone conduction sound collection unit configured to collect, as an acoustic signal, a sound of vibrations generated from a larynx and a pharynx of the subject via a cartilage region of the external auditory pore of the subject; a blood condition measuring unit configured to optically detect a pulsatory motion of blood circulating through blood vessels of the subject and measures a pulse rate and blood oxygen saturation, respectively, on the basis of a change in optical intensity caused by the pulsatory motion; a biological signal detection unit that includes a pair of conductive electrodes for detecting electric potentials of right and left external auditory pore surfaces, respectively, of the subject and is configured to detect brain waves and eye movements of the subject; a respiratory condition detection unit configured to detect, as a respiratory condition, sound quality, the number of times, a tidal volume, and a rhythm of breaths of the subject on the basis of the acoustic signal by the bone conduction sound collection unit ; a sleep state evaluation unit configured to evaluate a health condition of the subject while sleeping on the basis of the respiratory condition detected by the respiratory condition detection unit, the pulse rate and the blood oxygen saturation measured by the blood condition measuring unit , and the brain waves and the eye movements detected by the biological signal detection unit ; and a body temperature detection unit configured to detect a tympanic membrane temperature of the subject according to an infrared ray system, wherein the sleep state evaluation unit is configured to evaluate the subject's health condition while sleeping on the basis of synchronization timing between the pulse rate measured by the blood condition measuring unit and the tympanic membrane temperature detected by the body temperature detection unit . <EOS>