A pulse photometer includes: a first variation acquirer acquiring a first variation corresponding to a light attenuation variation of a first light beam due to pulsation of blood in a subject based on a first intensity signal corresponding to an intensity of the first light beam transmitted through or reflected from a body of the subject and having a first wavelength； a second variation acquirer acquiring a second variation； a third variation acquirer acquiring a third variation； a concentration calculator calculating a blood light absorber concentration based on the first variation and the second variation； an estimated value calculator calculating an estimated value of the third variation based on the first variation and the second variation； and an evaluator evaluating reliability of a calculated value of the blood light absorber concentration based on the third variation and the estimated value.
