A semiconductor device package includes a dielectric layer, a package body and a protection structure. The dielectric layer has a first surface, a second surface opposite to the first surface and a lateral surface extending between the first surface and the second surface. The package body is disposed on the first surface of the dielectric layer. The package body covers a first portion of the lateral surface of the dielectric layer and exposes a second portion of the lateral surface of the dielectric layer. The protection structure is disposed on the second portion of the lateral surface of the dielectric layer.