Non-volatile semiconductor memory device and erasing method for said device

An electrically erasable and writable non-volatile semiconductor memory device having a function of collectively erasing a plurality of memory blocks selected as erase object memory blocks is provided. A logic circuit and an output buffer circuit constitute an erase object memory block selection notifying circuit, which outputs an erase object memory block selection notifying signal indicating whether designated memory blocks have been selected as erase object memory blocks or not, in synchronization with an output enable signal supplied from the CPU. Thus, the erasing operation mode period in the non-volatile semiconductor memory device can be shortened.