Provided is a biological monitoring device capable of precisely detecting the sudden occurrence of an abnormality in a living body. A biological information measuring unit 33 measures biological information about a patient P for each predetermined measurement period by means of vital sensors 10, 11, and stores the measured biological information in a memory 32. A deviation degree calculating unit 34 calculates the degree of deviation in biological information for a predetermined measurement period Tw with reference to time-series data of the biological information stored in the memory 32. With respect to determined biological information, which is biological information measured at a predetermined time point after the measurement period Tw, a divergence calculating unit 35 calculates the divergence of the determined biological information from the deviation range of the biological information within the measurement period Tw. An abnormality determining unit 36 determines that the patient P is in an abnormal state when the divergence reaches a predetermined level or more.
