A damaged hair improving agent, including (A) an ester compound made from dipentaerythritol and at least one fatty acid having 5 to 16 carbon atoms, the molar ratio of dipentaerythritol residue to fatty acid residue ranging from 1.0:3.0 to 1.0:6.0, and one or more substances being either (B) an ester compound having a linear or branched alkyl or alkenyl group having 16 to 18 carbon atoms in which hydrogen atoms on these groups are replaced with hydroxyl groups, and a viscosity of 2,000 mPa·s or less at 25° C. (exclusive of (A)), (C) an alcohol having a linear or branched alkyl or alkenyl group having 16 to 18 carbon atoms and a viscosity of 2,000 mPa·s or less at 25° C., or (D) hydrocarbon oil having at least 20 carbon atoms. A sleek fell and reduction in gritty feel of hair are obtained.
