OPERATION METHOD OF NONVOLATILE MEMORY DEVICE

PURPOSE: An operation method of a nonvolatile memory device is provided to reduce a time required for an erase operation by simultaneously changing voltage to a word line and a well. CONSTITUTION: An erase command is inputted to eliminate the data stored in a memory cell(S301). A first voltage is applied to well and a second voltage is applied to a word line to perform an erase operation of the memory cell(S303). It is verified whether data saved in the memory cell is erased,(S305). If the data of the memory cell is not erased, the level of the second voltage is controlled to perform the erase operation while maintaining the level of the first voltage level is maintained(S307).