A non-volatile memory device includes a memory cell region including a first metal pad and a memory cell array including a plurality of memory cells, and a peripheral circuit region including a second metal pad and vertically connected to the memory cell region. The memory cell region includes a plurality of word lines, a ground selection line in a layer on the word lines, a common source line in a layer on the ground selection line, a plurality of vertical pass transistors in the stair area, and a plurality of driving signal lines in the same layer as the common source line. The word lines form a stair shape in the stair area, and each of the vertical pass transistors is connected between a corresponding one of the word lines and a corresponding one of the driving signal lines.