The herein disclosed technology provides a method of producing a carbon dioxide absorbing material that exhibits improved CO₂ absorption characteristics. This production method is a method of producing a carbon dioxide absorbing material in which a major component thereof is lithium silicate and includes the following steps: preparing a sol composition in which an Li Si precursor compound containing a lithium (Li) component and a silicon (Si) component is dispersed in an aqueous solution; obtaining a gel composition by exposing the sol composition to electromagnetic waves; and calcining the gel composition to obtain a lithium silicate containing lithium and silicon. As for a carbon dioxide absorbing material at least a part of a surface of the lithium silicate may be covered with a alkali carbonate. At least a part of the surface of this lithium silicate may be covered by an alkali carbonate.