A swallowing estimation device comprising: a biological sound detection means configured to detect biological sound at a larynx portion; respiration detection means configured to detect change in airflow of respiration; a signal intensity conversion means configured to convert biological sound data obtained by sampling the biological sound into signal intensity data; signal interval identification means configured to identify a signal interval having an intensity level higher than or equal to a noise level based on the signal intensity data; characterized in that it further comprises respiration identification means configured to identify an apneic interval based on airflow pressure data obtained by sampling change in the respiration; signal pulsing means configured to obtain a signal intensity that corresponds to a sampling timing in the apneic interval that is longer than or equal to a predetermined period and that overlaps the signal interval, and configured to generate a signal pulse having a width that corresponds to a period in which the signal intensity is greater than or equal to a predetermined level; swallowing reflex estimation means configured to estimate, as an estimated swallowing reflex interval, the apneic interval that satisfies a determination condition that the number of the signal pulses in the apneic interval longer than or equal to the predetermined period is less than or equal to a predetermined number and a width of each signal pulse in the apneic interval longer than or equal to the predetermined period is less than or equal to a predetermined period; and display means configured to display the estimated swallowing reflex interval. a biological sound detection means configured to detect biological sound at a larynx portion; respiration detection means configured to detect change in airflow of respiration; a signal intensity conversion means configured to convert biological sound data obtained by sampling the biological sound into signal intensity data; signal interval identification means configured to identify a signal interval having an intensity level higher than or equal to a noise level based on the signal intensity data; characterized in that it further comprises respiration identification means configured to identify an apneic interval based on airflow pressure data obtained by sampling change in the respiration; signal pulsing means configured to obtain a signal intensity that corresponds to a sampling timing in the apneic interval that is longer than or equal to a predetermined period and that overlaps the signal interval, and configured to generate a signal pulse having a width that corresponds to a period in which the signal intensity is greater than or equal to a predetermined level; swallowing reflex estimation means configured to estimate, as an estimated swallowing reflex interval, the apneic interval that satisfies a determination condition that the number of the signal pulses in the apneic interval longer than or equal to the predetermined period is less than or equal to a predetermined number and a width of each signal pulse in the apneic interval longer than or equal to the predetermined period is less than or equal to a predetermined period; and display means configured to display the estimated swallowing reflex interval.