An electronic sphygmomanometer determines whether a position of a measurement site falls within a proper range, and notifies whether the position of the measurement site falls within the proper range. When determination is made that a time in which the position of the measurement site falls within the proper range is not less than a predetermined time (for example, 2 seconds), measurement of a blood pressure is automatically started. When determination is made that a time in which the position of the measurement site is out of the proper range is not less than a predetermined time (for example, 5 seconds), the measurement of the blood pressure is started. Further, whether the position of the measurement site falls within the proper range is notified while correlated with the measurement result.