A field-effect transistor structure having two-dimensional transition metal dichalcogenides includes a substrate, a source/drain structure, a two-dimensional (2D) channel layer, and a gate layer. The source/drain structure is disposed on the substrate and has a surface higher than a surface of the substrate. The 2D channel layer is disposed on the source and the drain and covers the space between the source and the drain. The gate layer is disposed between the source and the drain and covers the 2D channel layer. The field-effect transistor having two-dimensional transition metal dichalcogenides is a planar field-effect transistor or a fin field-effect transistor.