An apparatus for estimating bio-information is provided. The apparatus for estimating bio-information according to an embodiment includes: an ultrasonic sensor configured to acquire a bio-signal from an object; and a processor configured to detect peaks from the bio-signal, and to determine false detection of a peak, among the detected peaks, by using at least one of a time interval between a current peak and an immediately preceding peak, amplitudes of the current peak and the immediately preceding peak, a shape of a waveform on a left region and a right region of the peak, and an occurrence position of the peak.