Semiconductor memory device and method of erasing the same

A semiconductor memory device according to an embodiment of the present invention, a plurality of memory blocks including a memory cell; A voltage supply circuit for providing a verify voltage for the erase and erase verify voltage for erasure of the selected memory block; And then subjected to erasure of the selected memory blocks, when performing the erase verification, share the word line group in units of the word line of the set number, The synthesis was carried out the erase verify in the word line group units each time the erase verify embodiment be an erase verify voltage or the pass voltage is gradually increased to a control logic including a circuit for controlling the voltage supply circuit.