In a memory device having a carbon nanotube and a method of manufacturing the same, the memory device includes a lower electrode, an upper electrode having a first void exposing a sidewall of a diode therein, an insulating interlayer pattern having a second void exposing a portion of the lower electrode between the lower electrode and the upper electrode, and a carbon nanotube wiring capable of being electrically connected with the diode of the upper electrode by a voltage applied to the lower electrode. The memory device may reduce generation of a leakage current in a cross-bar memory.