The present invention was made in view of the above-described circumstances, and an object of the invention is to provide an external skin preparation having a rough skin improving effect, excellent in texture in use, especially excellent in smoothness, free of sticky feeling, and excellent in stability. Another object is to provide a skin cleanser excellent especially in usability and a cosmetic removing effect. That is, the external skin preparation of the present invention is characterized by comprising a block-type alkylene oxide derivative represented by the below-described formula (I). [formula 1] Y—[O(EO)a-(AO)b-(EO)c-R]k  (I) (In the formula, Y is the residue given by removing hydroxyl groups from a polyhydric alcohol having 3 to 6 hydroxyl groups, and k is the number of hydroxyl groups of the polyhydric alcohol. EO is an oxyethylene group, AO is an oxyalkylene group having 3 to 6 carbon atoms, and they are attached in a block-type, respectively. The products, a×k, b×k, and c×k, are the average addition mole numbers of the oxyethylene group, the oxyalkylene group having 3 to 6 carbon atoms, and the oxyethylene group, respectively, and 0≦a×k≦100, 1≦b×k≦100, and 0≦c×k≦100, however, (a+c)×k>1. The percentage of all oxyethylene groups in formula (I) with respect to the sum of all oxyethylene groups and oxyalkylene groups having 3 to 6 carbon atoms in formula (I) is 10 to 80 mass %. Rs may be either identical to or different from each other, and they are hydrocarbon groups with 1 to 4 carbon atoms.) The skin cleanser of present invention is characterized by comprising 0.01 to 70 mass % of a block-type alkylene oxide derivative represented by the above-described formula (I) and 0.1 to 20 mass % of a moisturizer.