A package structure is provided. The package structure includes a substrate, a cover element, a semiconductor device, a protruding element, and an adhesive element. The cover element is disposed on the substrate and having a ring portion, a space is surrounded by the ring portion, and a recess is formed on a surface of the ring portion that faces the substrate. The semiconductor device is disposed on the substrate and disposed in the space surrounded by the ring portion, wherein the semiconductor device is spaced apart from the recess by the ring portion. The protruding element extends from the substrate and disposed in the recess. The adhesive element is disposed in the recess, wherein in a top view, the semiconductor device is surrounded by the protruding element.