Disclosed herein are a surgical navigation instrument having a needle electrode depth adjusting structure for detecting impedance and a high frequency energy control method using the same. The present invention can detect impedance of tissues while applying a pilot signal to an electrode of a high frequency needle according to impedance conditions of the tissues to detect impedance of the tissues, and determine an applied amount of high frequency energy output to high frequency needles according to the detected impedance, thereby reducing patients' pains, maximizing treatment effect, and reducing treatment time according to high frequency energy applied to various depths at the same treatment point when performing a surgical procedure with the same or different treatment parameters according to disease symptoms while selecting the insertion number of high frequency needles, which can be adjusted in penetration depth, into the skin.