An electronic clinical thermometer attachment unit, which is configured to be attached to an electronic clinical thermometer, inputs an external sound, determines whether the external sound is a buzzer sound notifying completion of measurement by the electronic clinical thermometer, based on whether the input external sound has a pattern of a buzzer sound notifying completion of the measurement, and performs notification output for notifying a user when it is determines that the external sound is a buzzer sound notifying completion of the measurement.