A 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:

R1—C(═O)—R2—C(═O)—R3—OSO3X

wherein R1, R2 and R3 are defined herein; X is H, a metal atom, NR44, imidazolium optionally containing a substituent, pyridinium optionally containing a substituent, or phosphonium optionally containing a substituent, where R4s are each H or an organic group and are the same as or different from each other; and any two of R1, R2, and R3 optionally bind to each other to form a ring. Also disclosed is a surfactant containing the sulfuric acid ester and an aqueous dispersant containing the sulfuric acid ester.