PROBLEM TO BE SOLVED: To provide a novel surfactant having good foaming power and excellent safety.SOLUTION: A (poly)glycerol monoether derivative of the present invention has a structure in which at least one of (n+1) hydroxyl groups of a (poly)glycerol monoether represented by formula (1): RO-(CHO)-H is substituted with a group selected from the group consisting of a group represented by formula (2): -OC(=O)-R-C(=O)ORand a group represented by formula (3): -O-R-C(=O)OR.SELECTED DRAWING: None【課題】良好な起泡力を有し、且つ安全性に優れる新規な界面活性剤を提供する。【解決手段】本発明の(ポリ)グリセリンモノエーテル誘導体は、下記式(1) R1O-(C3H6O2)n-H (1)で表される(ポリ)グリセリンモノエーテルの(n+1)個の水酸基の少なくとも1個が、下記式(2) -OC(=O)-R2-C(=O)OR3 (2)で表される基、及び下記式(3) -O-R4-C(=O)OR5 (3)で表される基からなる群より選択される基で置換された構造を有する【選択図】なし