PURPOSE: To provide a cosmetic having excellent feeling, giving excellent finished skin and stable in dermatological point of view.

CONSTITUTION: The objective cosmetic contains an alkenylsuccinic acid ester of a sugar produced by reacting a sugar with an alkenylsuccinic anhydride such as octenylsuccinic anhydride as a cosmetic base material. The sugar to be used as a starting raw material is monosaccharide, oligosaccharide, hydrolyzed starch, amino sugar, acidic sugar, sugar alcohol, saccharified reduced starch, reduced maltose syrup, etc. The amount of the alkenylsuccinic acid ester of sugar is preferably 0.1-15wt.% for a hair-care cosmetic such as shampoo and rinse and 0.5-30wt.% for a skin-care cosmetic such as cream. The compound has high affinity to the hair and skin and excellent film-forming property and adsorptivity to the hair, etc. The effect of the compound as protecting colloid can be maintained even by the addition of other surfactant to enable the combined use of other surfactants.