The present invention relates to an etchant composition for etching a triple film consisting of an indium-based metal film, an aluminum-lanthanum-based alloy film, and a titanium-based metal film, wherein the etchant composition comprises: 1 to 15 wt % of hydrogen peroxide; 0.1 to 10 wt % of inorganic acid; and 0.01 to 5 wt % of a fluorine compound, with the remainder being water.
