A bio-signal processing apparatus comprising: a first low pass filter, LPF, configured to have a first cutoff frequency, and output a first preprocessed signal having low frequency components of an input bio-signal that are less than the first cutoff frequency; a second LPF configured to have a second cutoff frequency, and output a second preprocessed signal in which high frequency components greater than or equal to the second cutoff frequency are removed from the input bio-signal; a delay buffer configured to adjust amounts of delay of the output second preprocessed signal and the output first preprocessed signal by appropriately adjusting a size of the delay buffer on the basis of a signal of the LPF that is delayed the most and output due to the lowest cutoff frequency and by connecting the delay buffer to an input port and/or an output port of the another LPF, wherein the first LPF partially shares the delay buffer with the second LPF; and a processor configured to output an output bio-signal for biometric information detection, based on the output first preprocessed signal and the output second preprocessed signal, wherein the processor is further configured to, in response to the first cutoff frequency and the second cutoff frequency being set to be different, and the output first preprocessed signal and the output second preprocessed signal being synchronized through the delay buffer: compare a magnitude of the output first preprocessed signal and a magnitude of the output second preprocessed signal to generate the output bio-signal; and detect an error of the generated output bio-signal, based on an amount of change in a time interval between pulse signals obtained by comparing the magnitudes of the output first preprocessed signal and the output second preprocessed signal. a first low pass filter, LPF, configured to have a first cutoff frequency, and output a first preprocessed signal having low frequency components of an input bio-signal that are less than the first cutoff frequency; a second LPF configured to have a second cutoff frequency, and output a second preprocessed signal in which high frequency components greater than or equal to the second cutoff frequency are removed from the input bio-signal; a delay buffer configured to adjust amounts of delay of the output second preprocessed signal and the output first preprocessed signal by appropriately adjusting a size of the delay buffer on the basis of a signal of the LPF that is delayed the most and output due to the lowest cutoff frequency and by connecting the delay buffer to an input port and/or an output port of the another LPF, wherein the first LPF partially shares the delay buffer with the second LPF; and a processor configured to output an output bio-signal for biometric information detection, based on the output first preprocessed signal and the output second preprocessed signal, wherein the processor is further configured to, in response to the first cutoff frequency and the second cutoff frequency being set to be different, and the output first preprocessed signal and the output second preprocessed signal being synchronized through the delay buffer: compare a magnitude of the output first preprocessed signal and a magnitude of the output second preprocessed signal to generate the output bio-signal; and detect an error of the generated output bio-signal, based on an amount of change in a time interval between pulse signals obtained by comparing the magnitudes of the output first preprocessed signal and the output second preprocessed signal. compare a magnitude of the output first preprocessed signal and a magnitude of the output second preprocessed signal to generate the output bio-signal; and detect an error of the generated output bio-signal, based on an amount of change in a time interval between pulse signals obtained by comparing the magnitudes of the output first preprocessed signal and the output second preprocessed signal.