Provided are a two-dimensional material structure, a semiconductor device including the two-dimensional material structure, and a method of manufacturing the semiconductor device. The two-dimensional material structure may include a first insulator including a first dielectric material; a second insulator on the first insulator and including a second dielectric material; a first two-dimensional material film on an exposed surface of the first insulator; and a second two-dimensional material film provided on an exposed surface of the second insulator. The first and second two-dimensional material films may include a two-dimensional material having a two-dimensional layered structure, and the second two-dimensional material film may include more layers of the two-dimensional material than the first two-dimensional material film.