According to an embodiment of the present disclosure, a biosignal measuring device comprises two channels respectively detecting bio-potential signals from a human body through two electrodes, a biosignal extracting unit including two detecting means respectively amplifying the bio-potential signals through amplifiers, respectively, differentially operating the amplified bio-potential signals through a differential operator, and selectively adopting respective output signals of the two detecting means to obtain a biosignal, and an impedance correcting means adjusting the amplitude of the amplifiers of the two detecting means so that the power of a common mode noise signal caused by an impedance imbalance between the channels and included in the obtained biosignal is reduced to suppress the common mode noise signal.
