Provided are a non-volatile memory device and a manufacturing method thereof. The non-volatile memory device includes a substrate having a memory region and a dummy region surrounding the memory region, an interconnect structure, memory cells, conductive vias and dummy vias. The interconnect structure is disposed on the substrate and in the memory region. The memory cells are disposed on the interconnect structure and arranged in an array when viewed from a top view. The memory cells include first memory cells in the memory region and second memory cells in the dummy region. The conductive vias are disposed in the memory region and between the first memory cells and the interconnection structure to electrically connect each of the first memory cells to the interconnect structure. The dummy vias are disposed in the dummy region and surround the memory region.