The present invention relates to a process for producing a glass doped with dispersed microcrystallites, which glass is used as a material for sharp cut filter, a material for infrared-transmitting filter, a nonlinear optical material, etc. In the process, high-melting semiconductor microcrystallites are precipitated at a temperature T.sub.1 which is lower than the sag point of a glass to be produced but not lower than the transition temperature of the glass, and then low-melting semiconductor microcrystallites are precipitated at a temperature T.sub.2 which is not higher than the flow point of the glass but not lower than the sag point of the glass to obtain a glass comprising a matrix and microcrystallites of semiconductor solid solution of multilayer structure dispersed in said matrix. This glass has solved, owing to the multilayer structure of the microcrystallites of semiconductor solid solution, the problem of conventional glasses doped with dispersed microcrystallites that the emission from the band edge of microcrystallites of semiconductor solid solution is hidden by the emission from the surface trap level.