A light-emitting discharge tube in which an outer wall surface of a glass tube is made less susceptible to flaws by forming a protective film on the outer wall surface of the glass tube, a method of fabricating the light-emitting discharge tube, and a protective film forming apparatus are provided. The light-emitting discharge tube defines light-emitting discharge regions by a plurality of external electrodes. The outer wall surface of the light-emitting discharge tube (the glass tube) is coated with the protective film (a metal film, a conductive metal oxide film, an insulating metal oxide film, or an organic film).