PURPOSE: To economically obtain a deep and expressive decorative glass product by arranging many glass gobs having devitrifiable surfaces and optional shapes in a prescribed area, then heating and softening the surfaces of the glass gobs, fusing and integrating the surfaces thereof and forming thin films containing minute devitrified substances in fused interfaces thereof.

CONSTITUTION: Many glass gobs 1 having devitrifiable surfaces and optional shapes are arranged in a prescribed area 2, then heated and softened to fuse and integrate the surfaces of the glass gobs 1. Thin films 4 containing minute devitrified substances are simultaneously formed in fused interfaces. Thereby, light scattering foggy or clouded thin films containing the extremely beautiful minute devitrified substances in the fused interfaces are formed in the resultant glass product 3. Any of soda-lime-based, borosilicate-based, lead silicate-based glasses, etc., can be used as the glass having the devitrifiable surfaces if the glass surfaces are devitrified by heating.