The present invention relates to an aqueous hair cleansing agent, comprising the following ingredients (A) and (B) and water: (A) a sulfate type anionic surfactant having a specific structure and (B) a polyoxyethylene alkyl ether type non-ionic surfactant having a specific structure, wherein the weight ratio of (B)/((A)+(B)) is 1%-25%.本發明係一種水性毛髮洗淨劑,其含有下述成分(A)、(B)及水:(A)具有特定構造之硫酸鹽型陰離子界面活性劑、(B)具有特定構造之聚氧乙烯烷基醚型非離子界面活性劑;且(B)/((A)+(B))之重量比例為1%~25%。