PURPOSE: To prevent exfoliation of a multilayered film due to continuous or intermittent thermal shock by forming a layer consisting of at least one kind of oxide among SiO2, Al2O3, oxide of P and B on the surface of a glass substrate before the formation of an oxide multilayered film.

CONSTITUTION: For example, an infrared rays reflecting film 2 is formed on the surface of a tube or bulb 1 consisting of transparent quartz glass of a tungsten halogen lamp by a dipping calcination method using an organometallic compd. soln. for this purpose, a soln. of alkoxy silane in alcohol and a soln. of titanium alkoxide in alcohol are prepd. wherein each solute is polymerized to some degree, forming an SiO2 coating soln. and TiO2 coating soln., and a P compd. is incorporated into the SiO2 coating soln. In the first stage, an oxide layer 3 contg. P-contg. SiO2 is formed on a bulb 1 with said SiO2 on the surface after cleaning the surface, then a layer 21 of a highly refractive substance consisting of TiO2 as the first layer of a multilayered film is formed with the TiO2 soln. Also, a layer 22 of a low refractive substance consisting of P-contg.-SiO2 is formed similarly as the layer 3, and the layer 21 and the layer 22 are formed alternately to obtain thus a film 2.