A crystal oscillator includes a cover, a crystal blank and an Integrated Circuit (IC) chip. The cover has a surface, a cavity formed in the surface, a plurality of conductive contacts and a conductive sealing ring. The conductive contacts are disposed on the surface, and the conductive sealing ring is disposed on the surface and surrounds the conductive contacts. The IC chip is connected to the conductive contacts and the conductive sealing ring, and forms a hermetic chamber with the cover and the conductive sealing ring. The crystal blank is located in the hermetic chamber, and is electrically connected to the IC chip. Furthermore, a method for manufacturing a crystal oscillator is also provided.