According to one embodiment, a pattern formation method contains: forming first guides by changing a surface energy of an underlayer material by transferring a pattern of a photomask onto the underlayer material by exposure, and forming second guides by changing the surface energy of the underlayer material between the first guides by diffraction of exposure light generated from the exposure; applying a block copolymer containing a plurality of types of polymer block chains onto the underlayer material; and causing any one of the polymer block chains to form a pattern in accordance with the first and second guides by microphase separation of the block copolymer by a heat treatment.