An apparatus for measuring bioelectrical impedance includes a current source configured to apply a constant current to an object through a first electrode and a second electrode a measurement mode switcher configured to switch a measurement mode from a first measurement mode to a second measurement mode in response to a measurement mode switch signal a voltmeter configured to obtain a voltage applied to a third electrode and a fourth electrode due to the constant current applied to the object and a processor configured to obtain first impedance based on a first voltage obtained by the voltmeter immediately before start of a measurement mode switch, obtain second impedance based on a second voltage obtained by the voltmeter immediately after completion of the measurement mode switch, and obtain bioelectrical impedance of the object based on the first impedance and the second impedance.
