A etchant composition that includes, based on a total weight of the etchant composition, about 0.5 wt % to about 20 wt % of a persulfate, about 0.5 wt % to about 0.9 wt % of an ammonium fluoride, about 1 wt % to about 10 wt % of an inorganic acid, about 0.5 wt % to about 5 wt % of a cyclic amine compound, about 0.1 wt % to about 10.0 wt % of a sulfonic acid, about 5 wt % to about 10 wt % of an organic acid or a salt thereof, and a remainder of water. The etchant composition may be configured to etch a metal layer including copper and titanium, to form a metal wire that may be included in a thin film transistor array panel of a display device.