A graphene-on-oxide substrate according to the present invention includes: a substrate having a metal oxide layer formed on its surface; and, formed on the metal oxide layer, a graphene layer including at least one atomic layer of the graphene. The graphene layer is grown generally parallel to the surface of the metal oxide layer, and the inter-atomic-layer distance between the graphene atomic layer adjacent to the surface of the metal oxide layer and the surface atomic layer of the metal oxide layer is 0.34 nm or less. Preferably, the arithmetic mean surface roughness Ra of the metal oxide layer is 1 nm or less.