Provided are a device for reading memory data and a method using the same. The device for reading memory data comprises a memory cell which stores multi-bit information, an information detection unit which detects as much bit information as a predetermined number of bits from among multi-bit information, a source-line voltage control unit which controls a source-line voltage of the memory cell based on the detected bit information from the information detection unit, and a remaining bit information read unit which reads remaining bit information stored in the memory cell by using the controlled source-line voltage.