Provided are a modifying agent for a plastic fat to be used in a plastic fat comprising palm oil, which inhibits changes in physical properties of the plastic fat such as hardness or crude crystal formation and gives an air-containing plastic fat and a plastic fat using the same. a plastic fat is prepared by using, as modifying agent, an appropriate amount of a fat composition which comprised triglycerides comprising, as constituting fatty acids, a saturated fatty acid (A) having a melting point of 60°C or higher and a saturated fatty acid (B) having a melting point of 40°C or lower, wherein the fat composition contains 40-85 wt%, relative to the total fat composition, of ABB type triglycerides, and the weight ratio (ABB/AAB) of said ABB type triglycerides o AAB type triglycerides is 2-15.