According to one embodiment, a semiconductor device includes a stacked body, a semiconductor body, and a stacked film. The stacked body includes a plurality of tungsten layers and a plurality of alloy layers of tungsten and molybdenum. At least portions of the tungsten layers are stacked with an air gap interposed. The alloy layers are provided on surfaces of the tungsten layers opposing the air gap. The semiconductor body extends in a stacking direction through the stacked body. The stacked film is provided between the semiconductor body and the tungsten layers. The stacked film includes a charge storage portion.