an electrode part in which a plurality of electrodes are arranged;

at least one processor configured to operate as a depth controller to configure electrode clusters from among the plurality of electrodes of the electrode part based on a measurement depth of the object, and generate a control signal, wherein the electrode clusters include a first electrode cluster comprising a first electrode and a second electrode disposed side by side in the plurality of electrodes, the first electrode and second electrode being connected to a first Y-axis signal line of a cross-point switch, and a second electrode cluster comprising a third electrode and a fourth electrode disposed side by side in the plurality of electrodes, the third electrode and the fourth electrode connected to a second Y-axis signal line of the cross-point switch, wherein the first electrode cluster and the second electrode cluster are controlled together;

the cross-point switch comprising a plurality of X-axis signal lines connected to each of the plurality of electrodes, the first Y-axis signal line and the second Y-axis signal line that intersect the X-axis signal lines, and configured to electrically connect the first electrode and the second electrode in the first electrode cluster to the first Y-axis signal line by switching on the X-axis signal lines connected to the first electrode and the second electrode in the first electrode cluster, and configured to electrically connect the third electrode and the fourth electrode in the second electrode cluster to the second Y-axis signal line by switching on the X-axis signal lines connected to the third electrode and the fourth electrode in the second electrode cluster, based on the control signal; and

a meter for measuring the impedance of the object based on signals measured through the electrode clusters,

wherein the depth controller is further configured to determine a width of the first and second electrode clusters and a gap between the first and second electrode clusters based on the measurement depth of the object, and

generate the control signal based on the width of the electrode clusters and the gap between the electrode clusters.