To provide a means for informing a measuring person that a satisfactory pulse wave is detected, by an analog circuit without using a software, in a pulse wave detector for detecting a pulse wave signal.

The pulse wave detector 91 for detecting the pulse wave signal is provided with: a photoelectric pulse wave detection part 11; an amplification part 12; an amplitude determination part 13; a buffer part 15; a reporting part 14; an A/D conversion part 21; an arithmetic part 22; and a display part 23. The pulse wave signal detected by the photoelectric pulse wave detection part 11 is outputted by an analog signal, and the amplitude determination part 13 shifts the base-line voltage of the analog signal to the ground level to make it possible to compare the amplitude of the pulse wave signal. Thereby, it is possible to determine that a satisfactory pulse wave is detected. Then, the reporting part 14 emits sound or light by a volume according to the amplitude of a level adjustment signal outputted by the amplitude judgement part 13.