SULFURIC ACID ESTER OR SALT THEREOF, AND SURFACTANT

The invention provides a novel sulfuric acid ester containing a plurality of carbonyl groups or a salt thereof, and a surfactant. The sulfuric acid ester is a compound represented by the following formula: R-C(=O)-R-C(=O)-R-OSOXwherein Ris a linear or branched alkyl group containing one or more carbon atoms or a cyclic alkyl group containing three or more carbon atoms, with a hydrogen atom that binds to a carbon atom being optionally replaced by a hydroxy group or a monovalent organic group containing an ester bond, the alkyl group optionally containing a carbonyl group when containing two or more carbon atoms, and the alkyl group optionally containing a monovalent or divalent heterocycle or being optionally in a cyclized form when containing three or more carbon atoms; Rand Rare each individually a single bond or a divalent linking group; R, R, and Rcontain six or more carbon atoms in total; X is H, a metal atom, NR, imidazolium optionally containing a substituent, pyridinium optionally containing a substituent, or phosphonium optionally containing a substituent, where Rs are each H or an organic group and are the same as or different from each other; and any two of R, R, and Roptionally bind to each other to form a ring.