A semiconductor device package includes a first conductive base, a first semiconductor die, a dielectric layer, a first patterned conductive layer, and a second patterned conductive layer. The first conductive base defines a first cavity. The first semiconductor die is on a bottom surface of the first cavity. The dielectric layer covers the first semiconductor die, the first surface and the second surface of the first conductive base and fills the first cavity. The first patterned conductive layer is on a first surface of the dielectric layer. The second patterned conductive layer is on a second surface of the dielectric layer.