Example embodiments of the present invention relate to an electrode structure, a method of manufacturing the electrode structure, a phase-change memory device having the electrode structure and a method of manufacturing the phase-change memory device. The electrode structure may include a pad, a first insulation layer pattern, a second insulation layer pattern and/or an electrode. The first insulation layer pattern may be formed on the pad. The first insulation layer pattern may have a first opening that partially exposes the pad. The second insulation layer pattern may be formed on the first insulation layer pattern. The second insulation layer pattern may have a second opening connected to the first opening. The electrode may be formed on the pad and filling the first and the second openings.