An ionization vacuum gauge includes a cathode electrode, a gate electrode, and an ion collector. The cathode electrode includes a base and a field emission film disposed thereon. The gate electrode is disposed adjacent to the cathode electrode with a distance therebetween. The ion collector is disposed adjacent to the gate electrode with a distance therebetween. The field emission film of the cathode electrode includes carbon nanotubes, a low-melting-point glass, and conductive particles.