Sidewall tracing nanoprobes, in which the tip shape of the nanoprobe Is altered so that the diameter or width of the very tip of the probe is wider than the diameter of the supporting stem. Such side protruding probe tips are fabricated by a subtractive method of reducing the stem diameter, an additive method of increasing the tip diameter, or sideway bending of the probe tip. These sidewall tracing nanoprobes are useful for inspection of semiconductor devices, especially to quantitatively evaluate the defects on the side wall of trenches or via holes.