Provided is a method of fabricating a graphene nano device. The method includes forming a first metal mask pattern on a substrate on which a graphene layer is formed, and forming a graphene pattern by performing an etching process on the graphene layer using the first metal mask pattern as an etching mask. The forming of the first metal mask pattern includes forming a first adhesive layer on the graphene layer, disposing the first metal mask pattern prepared in advance on the first adhesive layer, and heating the first adhesive layer to attach the first metal mask pattern on the substrate.