Abstract: An etchant composition is disclosed which includes hydrogen peroxide, an etch inhibitor, a chelating agent, an etch additive, an oxide semiconductor protective agent, and a pH regulator. The oxide semiconductor protective agent is included in the etchant composition by about 0.1˜3.0 wt % based on the total weight of the etchant composition. Such an etchant composition according to the present disclosure does not include any fluoride base compound and has a high pH value of about 3.5˜6. As such, the etchant composition allows an oxide semiconductor to not be etched in an etch process of copper and a molybdenum alloy. Therefore, the etchant composition can minimize faults that can be easily generated during the etching process.