Ion‐bombardment‐enhanced etching is suggested as an useful microfabrication technique for LiNbO3. Diluted HF was found to be a good selective etchant for a layer damaged by Ar+ and N+. This method is compared with another microfabrication method, ion beam etching. The accuracy of the pattern width by this method is better than that ion beam etching and the slope of the grooved wall is very steep. The etched depths of the layer damaged by 60‐keV Ar+ at the dose of 3×1015/cm2 and N+ at the dose of 2×1016/cm2 are 70 and 145 nm, respectively. The depth is controllable by changing the ion energy and dose.