According to one embodiment, a pattern formation method is disclosed. The method includes a preparation process, a block copolymer layer formation process, and a contact process. The preparation process includes preparing a pattern formation material including a block copolymer including a first block and a second block. The first block includes a first main chain and a plurality of first side chains. At least one of the first side chains includes a plurality of carbonyl groups. The block copolymer layer formation process includes forming a block copolymer layer on a first member. The block copolymer layer includes the pattern formation material and includes a first region and a second region. The first region includes the first block. The second region includes the second block. The contact process includes causing the block copolymer layer to contact a metal compound including a metallic element.