A carbon nanotube slurry consists of carbon nanotubes, glass powder, and organic carrier. The field emission device includes an insulative substrate, a cathode conductive layer, and an electron emission layer. The cathode conductive layer is located on a surface of the insulative substrate. The electron emission layer is located on a surface of the cathode conductive layer. The electron emission layer consists of a glass layer and a plurality of carbon nanotubes electrically connected to the cathode conductive layer.