According to one embodiment, a nonvolatile semiconductor memory device includes: a semiconductor layer; a first insulating film provided on the semiconductor layer; a floating gate layer provided on the first insulating film; a second insulating film provided on the floating gate layer; and a gate electrode provided on the second insulating film, the first insulating film including silicon, oxygen, and carbon. Concentration of the carbon in a direction from the semiconductor layer side toward the floating gate layer side has a maximum between the semiconductor layer and the floating gate layer, and the maximum being located nearer to the semiconductor layer side than to the floating gate layer side.