An etchant composition including a persulfate, a four-nitrogen ring compound, a carbonyl ring compound having two or more carbonyl groups, and water, and having a weight ratio of the four-nitrogen ring compound and the carbonyl ring compound of about 1:0.1 to about 1:2. The etchant composition may etch a multilayer of titanium/copper and may be used for manufacturing a metal pattern and an array substrate having excellent properties of an etched pattern.