PURPOSE: To manufacture a lightning insulator excellent in strength, reliability, and in mass production by providing a tapered transparent hole on an umbrella part of the glass main body, by inserting another cylinder for lightning protection device storage provided with a taper on its peripheral surface, in the transparent hole, with an inorganic binding material present intermediately on the periphery, and by baking it.

CONSTITUTION: A glass main body 1 composed of porcelain material is molded, and when the main body 1 is in a raw material condition, on an umbrella part 2 thereof, a tapered transparent hole 3 is provided using a tapered reamer. Angle of the taper is defined as 1-3 degrees. A cylinder 4 for lightning protection device storage in a raw material condition which is of the same material as the main body 1 and which has a common taper on its peripheral surface is molded in another process, and with an inorganic binding material such as a glazing chemical or glass present intermediately on its peripheral surface, it is inserted into the hole 3. When it is baked with a load applied, both of them are solidly integrated with each other, and a lightning protection glass can thus be manufactured. Baking can be performed after each of the cylinder 4 and the main body 1 is baked respectively, and after the inorganic binding material layer is placed between them.