The present invention relates to a hair treating agent containing (a) an organic acid represented by the formula (1), an organic acid represented by the formula (2) or their salts and (b) a quaternary ammonium salt, a tertiary amine or a salt thereof:wherein R1 and R2 independently represent an alkyl or hydroxyalkyl group having 1 to 5 carbon atoms or —R8—COOH, R3, R4 and R8 independently represent an alkylene group having 1 to 5 carbon atoms, R5 represent an alkyl or hydroxyalkyl group having 1 to 5 carbon atoms or —R9—COOH and R6, R7 and R9 independently represent an alkylene group having 1 to 5 carbon atoms.
