a blood pressure surge detection part to detect, based on predetermined determination criteria, blood pressure surges from time-series blood pressure data of a subject that varies with pulsation;

a feature amount calculation part to obtain a feature amount indicating a characteristic of each blood pressure surge detected, wherein the feature amount includes at least a surge variation amount and a surge peak value;

a statistical amount calculation part to perform statistical processing on an occurrence number of the blood pressure surges detected and the feature amount to obtain a statistical amount for each of a plurality of time slots, the statistical amount including at least the occurrence number of the blood pressure surges, a surge variation amount statistic and a surge peak value statistic;

a required attention degree calculation part to obtain, based on a result of comparison for the occurrence number of the blood pressure surges, the surge variation amount statistic and the surge peak value statistic included in the statistical amount with respective predetermined thresholds, a required attention degree indicating a level of attention being required to the blood pressure surge for each of the time slots; and

a display processing part to display, for each of the time slots, the required attention degree obtained and the statistical amount on a display screen, wherein

an individual index calculation part to obtain, for each of the time slots, individual indexes respectively indicating a level of attention being required for the occurrence number of the blood pressure surges, the surge variation amount statistic and the surge peak value statistic as one of m levels according to the level of attention being required based on a result of comparison with respective (m−1) predetermined thresholds different in magnitude, and

an integration processing part to obtain, for each of the time slots, the required attention degree as one of the m levels by using the individual indexes respectively obtained for the occurrence number of the blood pressure surges, the surge variation amount statistic and the surge peak value statistic, wherein

set, on the display screen, a plurality of closed areas respectively corresponding to the time slots side by side along progress of the time slots,

apply, to each of the closed areas, a specific color according to the level of the required attention degree in a corresponding one of the time slots, and

display, on the display screen, a graph showing the statistical amount with the graph superimposed on each of the closed areas, such that the required attention degree and the statistical amount obtained for a first time slot is displayed side by side with the required attention degree and the statistical amount obtained for a second time slot.