In a pulse wave analyzer, a local maximum point of a fourth order differentiated wave of the pulse wave of one beat is acquired, and a maximum point of a reflection wave of the local maximum points of the fourth order differentiation existing in a zone of an original waveform is determined as a starting point of a reflection wave zone that is a first characteristic point. With 10% of the amplitude of the first characteristic as a threshold value, a time point at which the amplitude reaches the threshold value after the relevant point is determined as an ending point of the reflection wave zone that is a second characteristic point. The duration time of the reflection time of the time between the first characteristic point and the second characteristic point is calculated as an index useful in the diagnosis of heart disease.