The invention relates to a surfactant composition containing an alkyl sulfate salt derivative represented by the following formula (1). €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒR-O - (PO) n -SO 3 M€ƒ€ƒ€ƒ€ƒ€ƒ(1) wherein R represents a straight-chain alkyl group having 8 to 24 carbon atoms, PO represents a propylene oxide group, n denotes the average number of added moles of PO and is a number satisfying : 0 < n ‰¦ 0.9. M represents a cation.
