A method for synthesizing alkali metal silicate which can be easily microparticulated, a method for synthesizing, with the use of the alkali metal silicate, alkali transition metal silicate, and alkali metal silicate and alkali transition metal silicate which are synthesized by the synthesis methods are disclosed. The alkali metal silicate is synthesized by the following steps: forming a basic solution including an alkali metal salt; mixing the basic solution including the alkali metal salt with silicon particles to form a basic solution including the alkali metal silicate; and adding the basic solution including the alkali metal silicate to a poor solvent for the alkali metal silicate to precipitate the alkali metal silicate. Further, the alkali metal silicate is mixed with a microparticulated compound including a transition metal to form a mixture, and the mixture is subjected to heat treatment, whereby the alkali transition metal silicate is generated.