Methods of manufacturing a phase-change memory device and a semiconductor device are provided. The method of manufacturing the phase-change memory device includes forming a switching device layer, an ohmic contact layer, and a hard mask layer on a semiconductor substrate, patterning the hard mask layer to form a hard mask pattern, etching the ohmic layer and the switching layer using the hard mask pattern to form a pattern structure including an ohmic contact pattern, a switching device pattern, and the hard mask pattern, selectively oxidizing a surface of the pattern structure, forming an insulating layer to bury the pattern structure, and selectively removing the hard mask pattern other than the oxidized surface thereof to form a contact hole.