Provided are: a ceramide-like function imparting agent which imparts a function similar to that of a ceramide； a skin barrier function reinforcing agent； a moisturizing agent； and an external preparation for the skin. A ceramide-like function imparting agent which contains, as an active ingredient, a succinic acid diamide derivative represented by formula (1). (In the formula, each of R1 and R2 independently represents a hydroxyalkyl group having 1-6 carbon atoms； and R3 represents a -CH2CH2CH2CH2-R4 group or a -CH2CH=CHCH2-R4 group (wherein R4 represents an alkyl group having 8-26 carbon atoms)).本發明提供一種賦予與神經醯胺相同功能之類神經醯胺功能賦予劑、皮膚屏障功能補強劑、保濕劑、及皮膚外用劑。本發明之類神經醯胺功能賦予劑係以下述式(1)所表示之琥珀二醯胺衍生物作為有效成分[式中，R1及R2獨立地表示碳數1~6之羥基烷基，R3表示基-CH2CH2CH2CH2-R4或基-CH2CH=CHCH2-R4(此處，R4表示碳數8~26之烷基)]。
