A blood pressure decrease prediction apparatus is provided with: a pulse rate calculating device (110) for calculating a pulse rate of a living body, based on a blood flow waveform which represents a temporal variation of a blood flow volume of the living body； a blood flow volume calculating device (120) for calculating the blood flow volume of the living body, based on the blood flow waveform； and a blood pressure decrease predicting device (140) for predicting the decrease of the blood pressure, based on a variation of each of the calculated pulse rate and the calculated blood flow volume.
