An object of the present invention is to provide an external preparation containing memantine which has less skin irritation and excellent skin permeability, and also, which is suitable for continuous administration for a long period of time.The external preparation according to the present invention comprises memantine or a salt thereof, and further comprises 0.05 to 1.5% by weight of phosphatidylcholine, 35 to 55% by weight of propylene glycol, 18 to 30% by weight of glycerine, and 22 to 32% by weight of water. The content of water less than 22% by weight may increase skin irritation, and the content of water more than 32% by weight may decrease skin permeability. The content of glycerin less than 18% by weight may increase skin irritation, and the content of glycerin more than 30% by weight may decrease skin permeability.
