A composite substrate structure includes a circuit substrate, a first anisotropic conductive film, a first glass substrate, a dielectric layer, a patterned circuit layer and a conductive via. The first anisotropic conductive film is disposed on the circuit substrate. The first glass substrate is disposed on the first anisotropic conductive film and has a first surface and a second surface opposite to the first surface. The first glass substrate includes a first circuit layer, a second circuit layer and at least one first conductive via. The first circuit layer is disposed on the first surface. The second circuit layer is disposed on the second surface. The first conductive via penetrates the first glass substrate and is electrically connected to the first circuit layer and the second circuit layer. The first glass substrate and the circuit substrate are respectively located on two opposite sides of the first anisotropic conductive film.