An apparatus (100, 1000, 1100) for measuring a biosignal, comprising: an optical sensor (110, 1010) configured to emit light in a measurement region to an object of interest, and receive an optical signal reflected from the object of interest; a bioelectrical impedance sensor (120, 1020) configured to measure a depth-specific bioelectrical impedance in the measurement region of the optical sensor, wherein the bioelectrical impedance sensor comprises: at least a first electrode and a second electrode which are spaced a predetermined distance apart from each other and are disposed symmetrically with respect to the optical sensor; and an impedance measurer configured to measure a first bioelectrical impedance at a first depth in the measurement region of the optical sensor and measure a second bioelectrical impedance at a second depth in the measurement region of the optical sensor, wherein the first depth and the second depth are different from each other, and wherein the bioelectrical impedance sensor is configured to measure the first bioelectrical impedance at the first depth and the second bioelectrical impedance at the second depth by adjusting a spacing of the electrodes, an area of the electrodes, or a measurement frequency; and the apparatus further comprises: a processor configured to determine biometric information of the object of interest based on the received optical signal and the depth-specific bioelectrical impedance by using a biometric information estimation model, wherein the biometric information estimation model defines a relationship between the optical signal, the depth-specific bioelectrical impedance and the biometric information. an optical sensor (110, 1010) configured to emit light in a measurement region to an object of interest, and receive an optical signal reflected from the object of interest; a bioelectrical impedance sensor (120, 1020) configured to measure a depth-specific bioelectrical impedance in the measurement region of the optical sensor, wherein the bioelectrical impedance sensor comprises: at least a first electrode and a second electrode which are spaced a predetermined distance apart from each other and are disposed symmetrically with respect to the optical sensor; and an impedance measurer configured to measure a first bioelectrical impedance at a first depth in the measurement region of the optical sensor and measure a second bioelectrical impedance at a second depth in the measurement region of the optical sensor, wherein the first depth and the second depth are different from each other, and wherein the bioelectrical impedance sensor is configured to measure the first bioelectrical impedance at the first depth and the second bioelectrical impedance at the second depth by adjusting a spacing of the electrodes, an area of the electrodes, or a measurement frequency; and at least a first electrode and a second electrode which are spaced a predetermined distance apart from each other and are disposed symmetrically with respect to the optical sensor; and an impedance measurer configured to measure a first bioelectrical impedance at a first depth in the measurement region of the optical sensor and measure a second bioelectrical impedance at a second depth in the measurement region of the optical sensor, wherein the first depth and the second depth are different from each other, and wherein the bioelectrical impedance sensor is configured to measure the first bioelectrical impedance at the first depth and the second bioelectrical impedance at the second depth by adjusting a spacing of the electrodes, an area of the electrodes, or a measurement frequency; and the apparatus further comprises: a processor configured to determine biometric information of the object of interest based on the received optical signal and the depth-specific bioelectrical impedance by using a biometric information estimation model, wherein the biometric information estimation model defines a relationship between the optical signal, the depth-specific bioelectrical impedance and the biometric information.