An apparatus for biometric information detection includes a housing, a biometric sensor (e.g. an optical sensor) disposed on a surface of the housing, and configured to detect biometric information of a subject, and an impedance measurer including at least two electrode pairs disposed around the biometric sensor, the impedance measurer being configured to measure bio-impedances of the subject using the electrode pairs. The apparatus further includes a processor configured to determine a bio-impedance ratio of the measured bio-impedances, and to determine validity of the detected biometric information, based on the determined bio-impedance ratio.
