The present invention provides a chip package, including: a chip having a semiconductor device thereon; a cap layer over the semiconductor device; a spacer layer between the chip and the cap layer, wherein the spacer layer surrounds the semiconductor device and forms a cavity between the chip and the cap layer; and an anti-reflective layer between the cap layer and the chip, wherein the anti-reflective layer has a overlapping region with the spacer layer and extends into the cavity. Furthermore, a method for fabricating a chip package is also provided.