According to one embodiment, a method for manufacturing a semiconductor device includes forming a plurality of recess portions on a first surface of a support. Each recess portion is between protrusion portions on the first surface. A stacked body is then placed into each of the recess portions. The stacked body is a plurality of semiconductor chips stacked on each other or the like. The recess portions are filled with a resin layer. The resin layer covers the stacked bodies inside the recess portions. A protrusion portion of the support is irradiated with a laser beam to form a modified portion in the protrusion portion. The support is divided along the protrusion portions into separate pieces.