A pulse oximeter may include a photoelectric conversion device having wavelength selectivity so that a low output LED may be included in the pulse oximeter to prevent skin damage and to reduce power consumption. The pulse oximeter includes a light emitting device configured to emit white light and a sensor configured to detect transmitted light that is received from the light emitting device. The sensor includes a near infrared organic photoelectric conversion device configured to sense a particular near infrared wavelength spectrum of light and a red photoelectric conversion device configured to sense a particular red wavelength spectrum of light.
