A wiring structure includes a first insulation layer, a plurality of wiring patterns, a protection layer pattern and a second insulation layer. The first insulation layer may be formed on a substrate. A plurality of wiring patterns may be formed on the first insulation layer, and each of the wiring patterns may include a metal layer pattern and a barrier layer pattern covering a sidewall and a bottom surface of the metal layer pattern. The protection layer pattern may cover a top surface of each of the wiring patterns and including a material having a high reactivity with respect to oxygen. The protection layer pattern may cover a top surface of each of the wiring patterns and including a material having a high reactivity with respect to oxygen.