Provided is an external agent for treating hyperhidrosis, said external agent comprising water, an anticholinergic and one or more salts selected from the group consisting of a lactate, tartrate, acetate and phosphate. This external agent comprises the salt(s) specified above, which facilitates the accumulation of the anticholinergic in an appendage of the skin.本發明提供多汗症治療用外用劑，其包含水、抗膽鹼作用藥以及自乳酸鹽、酒石酸鹽、乙酸鹽及磷酸鹽所成之群選擇之1種以上之鹽。該外用劑中由於包含上述特定鹽，故易對於皮膚之附屬器官累積抗膽鹼作用藥。
