A nonvolatile semiconductor memory device according to one aspect includes a semiconductor substrate, a memory string, a plurality of first conductive layers, a second conductive layer, and a third conductive layer. The memory string has a plurality of memory cells, a dummy transistor and a back gate transistor connected in series in a direction perpendicular to the semiconductor substrate. The plurality of first conductive layers are electrically connected to gates of the memory cells. The second conductive layer is electrically connected to a gate of the dummy transistor. The third conductive layer is electrically connected to a gate of the back gate transistor. The second conductive layer is short-circuited with the third conductive layer.