A semiconductor device package includes a substrate, a stacked structure and an encapsulation layer. The substrate includes a circuit layer, a first surface and a second surface opposite to the first surface. The substrate defines at least one cavity through the substrate. The stacked structure includes a first semiconductor die disposed on the first surface and electrically connected on the circuit layer, and at least one second semiconductor die stacked on the first semiconductor die and electrically connected to the first semiconductor die. The second semiconductor die is at least partially inserted into the cavity. The encapsulation layer is disposed in the cavity and at least entirely encapsulating the second semiconductor die.