A non-volatile memory device is provided. In an aspect, the non-volatile memory device includes two or more common source lines that are included in one memory cell block in order to distribute the current that could have been concentrated on one common source line. As a result, the bouncing phenomenon generated by the nose of the source line can be reduced. That is, at the time of a verifying operation performed during a program operation, the current concentrated on a common source line can be distributed and, therefore, the occurrence of under-programmed cells can be prevented.