To provide a surely controllable gas discharge lamp which prevents discharge dielectrically under high output of a discharge lamp for a long time.

With the gas discharge lamp which prevents discharge dielectrically, a discharge tube of the gas discharge lamp is filled with gas, and is composed of a wall of at least a dielectric material and a wall having a surface through which a discharge is partially visible, which are covered by a luminous layer consisting of a luminous body sample and a coating of luminous powder. The coating is composed of a compound selected from among the group of fluoride consisting of elements such as magnesium, calcium, barium, aluminum, scandium, yttrium, and lanthanum as well as orthophosphate, which has an electrode structure dielectrically preventing discharge and is made up of a method of dielectrically maintaining prevention of discharge.