A memory includes first selective transistors connected between one end of cell strings and bit lines; second selective transistors connected between the other end of the cell strings and a cell source line; a dummy cell string; a first dummy selective transistor connected between one end of the dummy cell string and a dummy bit line and whose gate is connected to a first selective gate line; a second dummy selective transistor connected between the other end of the dummy cell string and the cell source line and whose gate is connected to a second selective gate line, wherein at a time of writing in a selected memory cell, a voltage of a first dummy bit line selected is driven to a different voltage from a voltage of an unselected bit line, and any of the dummy cell transistors connected to the first dummy bit line is written.