Two-dimensional materials refer to materials that have a thickness equal to one or several layers of atoms and exist independently of the outside, and are often obtained by physically separating them from three-dimensional bulk materials. A typical two-dimensional material is graphene, which corresponds to one layer of atoms of graphite, which is a layered structure. Interestingly, two-dimensional materials exhibit a new physical phenomenon different from the parent three-dimensional bulk state. In this laboratory, 1) micro-sized electronic devices are manufactured with two-dimensional materials and 2) electron transport mechanisms derived from 3) electronic structures of materials are studied through electrical measurements.