A medical apparatus includes a light emitter configured to emit light beams of different wavelengths to living tissue, a light detector configured to detect the light beams of different wavelengths emitted from the light emitter, an acquiring section that calculates absorbances of arterial blood for the respective light beams of different wavelengths based on the light beams detected by the light detector, that acquires a pulse waveform based on the absorbances, and that acquires a parameter corresponding to an oxygen saturation from a ratio of the absorbances, a detecting section that detects variation of the parameter corresponding to the oxygen saturation acquired by the acquiring section, and an evaluating section that evaluates the pulse waveform acquired for a purpose of pulse wave analysis by the acquiring section based on a result of the detection by the detecting section.
