Provided are a nonvolatile memory device and a method of fabricating the same, in which a phase-change layer is formed using a solid-state reaction to reduce a programmable volume, thereby lessening power consumption. The device includes a first reactant layer, a second reactant layer formed on the first reactant layer, and a phase-change layer formed between the first and second reactant layers due to a solid-state reaction between a material forming the first reactant layer and a material forming the second reactant layer. The phase-change memory device consumes low power and operates at high speed.