A graphene switching device includes a first electrode and an insulating layer in first and second regions of the semiconductor substrate, respectively, a plurality of metal particles on a surface of the semiconductor substrate between the first and second regions, a graphene layer on the plurality of metal particles and extending on the insulating layer, a second electrode on the graphene layer in the second region and configured to face the insulating layer, a gate insulating layer configured to cover the graphene layer, and a gate electrode on the gate insulating layer. The semiconductor substrate forms an energy barrier between the graphene layer and the first electrode.