A pulse rate counting device includes: a short-term average value calculation unit for calculating an average interval of predetermined previous pulses a fluctuation amount calculation device for calculating the amount of fluctuation on the basis of the difference between the average interval and an actual pulse wave interval a search range determination unit for calculating the width of the search range, calculating an amount of displacement on the basis of a time change of the average interval, and determining as a search range a range including an appearance prediction value of the next detection point calculated from the average interval and indicated by the width of the search range from a starting point determined on the basis of the amount of displacement and a pulse wave interval detection unit for detecting the detection point in the determined search range, and outputting a pulse wave interval.
