An inventive nonvolatile semiconductor memory device is provided, in advance, with a column latch circuit 29 for performing a batch write operation (page latching operation, page programming operation, and verifying operation), and the column latch circuit 29 is utilized to realize a security function. The inventive memory device is further provided with a security control circuit 41 for carrying out control so that a password for deactivating the security function is stored in the column latch circuit 29 and a verifying operation is performed to determine whether the password stored in the column latch circuit 29 is identical to a security function deactivation code stored in a deactivation code storage 13. If it is determined that the password and the security function deactivation code are identical as a result of the verifying operation, the security function is deactivated.