An apparatus for detecting a defect of a battery pack, comprising: a voltage measuring unit configured to measure a voltage of a battery cell through a sensing line; a filter unit having a capacitor provided to correspond to the battery cell and configured to filter a noise included in the voltage measured by the voltage measuring unit through the capacitor with respect to the corresponding battery cell; the apparatus is characterized in that it comprises: a signal output unit connected to the filter unit through a line having a noise resistor (Rn) and configured to output a noise signal having an output frequency corresponding to frequency information to the filter unit when a control signal having the frequency information is input; and a control unit connected to the voltage measuring unit and the signal output unit and configured to send the control signal having the frequency information to the signal output unit, receive the voltage value of the battery cell including the noise signal having a frequency band which is partially filtered by the filter unit, the voltage value being measured by the voltage measuring unit and detect a defect of the capacitor included in the filter unit based on the received voltage value of the battery cell and a preset reference value. a voltage measuring unit configured to measure a voltage of a battery cell through a sensing line; a filter unit having a capacitor provided to correspond to the battery cell and configured to filter a noise included in the voltage measured by the voltage measuring unit through the capacitor with respect to the corresponding battery cell; the apparatus is characterized in that it comprises: a signal output unit connected to the filter unit through a line having a noise resistor (Rn) and configured to output a noise signal having an output frequency corresponding to frequency information to the filter unit when a control signal having the frequency information is input; and a control unit connected to the voltage measuring unit and the signal output unit and configured to send the control signal having the frequency information to the signal output unit, receive the voltage value of the battery cell including the noise signal having a frequency band which is partially filtered by the filter unit, the voltage value being measured by the voltage measuring unit and detect a defect of the capacitor included in the filter unit based on the received voltage value of the battery cell and a preset reference value. a signal output unit connected to the filter unit through a line having a noise resistor (Rn) and configured to output a noise signal having an output frequency corresponding to frequency information to the filter unit when a control signal having the frequency information is input; and a control unit connected to the voltage measuring unit and the signal output unit and configured to send the control signal having the frequency information to the signal output unit, receive the voltage value of the battery cell including the noise signal having a frequency band which is partially filtered by the filter unit, the voltage value being measured by the voltage measuring unit and detect a defect of the capacitor included in the filter unit based on the received voltage value of the battery cell and a preset reference value.