A semiconductor device with a cavity structure comprises: a carrier substrate; a first die having an active surface and the pads thereon; a back surface of the first die is disposed on the carrier substrate; a second die having a top surface and a back surface and a cavity structure therein; the top surface of a second die is flipped to dispose on the first die, and the cavity structure is an inverse U-type to dispose between the active surface of the first die and the top surface of the second die; the wires is electrically connected the pads with the first connecting points; a package body encapsulated the first die, the second die, the wires, and the portion of the top surface of the carrier substrate; and the connecting components is disposed on the back surface of the carrier substrate and is electrically connected the second connecting points.