A memory device, which includes a memory layer having quantum dots uniformly dispersed in organic material disposed between an upper electrode layer and a lower electrode layer. The memory device is advantageous because it is nonvolatile and inexpensive, and realizes high integration and high speed switching. Further, size and distribution of the quantum dots may be uniform, thus realizing uniform memory behavior. Furthermore, the memory device is suitable for application to portable electronic devices that must have low power consumption, due to low operating voltages thereof.