Disclosed are embodiments of an apparatus for correcting an offset of a current sensor. The apparatus includes an inverter, a detector, and a RMS calculator, and a controller. The RMS calculator converts the high frequency component extracted from the filter into an effective (RMS) value. The controller, if the effective (RMS) value of the d-axis or q-axis current transformed by the RMS calculator is larger than a preset reference, increases/decreases a currently-set DC offset of each of the current sensors by a certain amount, and replaces the currently-set DC offsets with a DC offset corresponding to a smallest one of the effective (RMS) values of the d-axis or q-axis transformed by the RMS calculator, thereby correcting each of the current sensors. Accordingly, a pulsation in an output torque in controlling an electric motor can be effectively prevented.