A semiconductor device package includes a substrate, a first encapsulant and a second encapsulant. The substrate has an optical region and a surface-mount technology (SMT) device region. The first encapsulant includes a first portion disposed on the optical region and covers the optical region and a second portion disposed on the SMT device region and covers the SMT device region. The second encapsulant is disposed on the substrate and covers at least a portion of the second portion of the first encapsulant and a portion of the first portion of the first encapsulant.