In a phase change memory, an interlayer insulating layer is disposed on a substrate. A heater plug includes a lower portion disposed in a contact hole penetrating the interlayer insulating layer and an upper portion protruding upward over the top surface of the interlayer insulating layer. A phase change pattern is disposed on the interlayer insulating layer to cover the top surface and the side surface of the protruding portion of the heater plug. An insulating spacer is interposed between the phase change pattern and the side surface of the protruding portion of the heater plug. A capping electrode is disposed on the phase change pattern.