PROBLEM TO BE SOLVED: To provide a curable composition having a weight reduction in specific gravity and good curable property even when curable material thereof is applied to a thin layer, and capable of maintaining a good condition of a coating film when coated on it, and to provide the cured material having low modulus, high elongation and high strength.SOLUTION: A curable composition contains (A) a reactive silicon group-containing polymer which may crosslink by forming a siloxane bond, (B) micro balloons, (C) a carboxylic acid metal salt, and further contains at least one of (D) a secondary amine compound having 12 or more total carbon atoms in a molecule and (D) a guanidine compound having an aryl group.
