To produce a building material high in an additional value by effectively utilizing many wastes which increase year after year.

This method for producing crystalline glass comprises effectively utilizing natural materials, general and industrial wastes, the incinerated ash of the general or industrial wastes, etc., using coloring components contained in the materials or adding a coloring agent. Therein, a composition comprising 1.0-12.0wt.% of alumina (Al2O3), 7.0-20.0wt.% of alkali compounds (Na2I+K2O+ Li2O), and boron oxide (B2O3), barium oxide (BaO), zinc oxide (ZnO), etc., as melting agents except the alkali compounds, and, if necessary, further magnesium oxide (MgO), fluorine(F), chlorine(Cl), sulfur(S) and carbon(C) so that the ratio of silicon (SiO2) to calcium oxide (CaO) is 13-5.2 is prepared and subsequently melted and thermally treated at a relatively low temperature.