A semiconductor memory device including: a cell array with electrically
rewritable and non-volatile memory cells arranged therein; a sense
amplifier circuit configured to read data of and write data into the cell
array; and a controller configured to control read, write and erase of
the cell array, wherein the controller executes an erase sequence for
erasing a selected block in the cell array in response to erase command
and address input in such a way of: executing a first erase-verify
operation for verifying an erase state of the selected block; ending the
erase sequence if the erase state of the selected block has been verified
by the first erase-verify operation; whereas executing an erase operation
for the selected block if the erase state has not been verified.