Abstract: A hair treatment agent containing the following components (A) to (D) and water: (A) succinic acid or a salt thereof: 0.1 mass % or more and 2 mass % or less in terms of succinic acid; (B) erythritol: 0.5 mass % or more and 15 mass % or less; (C) at least one aromatic alcohol selected from the group consisting of benzyl alcohol, phenoxyethanol and benzyloxyethanol; and (D) at least one of polyoxyalkylene glycol with an alkylene group having 2 or 3 carbon atoms: 0.01 mass % or more and 5 mass % or less, in which the mass ratio of component (C) to component (D), (C)/(D), is 0.1 or more and 20 or less.