A method of forming patterns includes forming an etch target film on a substrate having a first region and a second region, forming a hardmask structure on the etch target film in the first region and the second region, the hardmask structure including a plurality of hardmask layers, forming a first photoresist film on the hardmask structure in at least one of the first region and the second region, forming a first photoresist pattern in the second region by exposing and developing the first photoresist film, and forming a pattern from the etch target film by etching the hardmask structure and the etch target film by using the first photoresist pattern, wherein a top surface of the hardmask structure in the first region is exposed to the outside after the first photoresist film is developed.