The present invention is to provide a new compound having a rough skin improving effect, excellent in safety, excellent in texture in use, especially free of sticky feeling, excellent in refreshing feeling, and capable to improve the base agent stability as a component. An alkylene oxide derivative is characterized by being represented by the below-described general formula (I): (formula I) Z-{O-[(AO)a-(EO)b]-R}2  (I) (In the formula, Z is the residue obtained by removing hydroxyl groups from the dimer diol, EO is an oxyethylene group, AO is an oxyalkylene group having 3 to 4 carbon atoms, and the addition form is block-type. The symbols a and b are the average addition mole numbers of the above-described oxyalkylene group and the oxyethylene group, respectively, and they are 1≦2 a≦150 and 1≦2 b≦150. The percentage of the oxyethylene groups with respect to the sum of the oxyalkylene groups having 3 to 4 carbon atoms and the oxyethylene groups is 10 to 99 mass %. Rs may be either identical to or different from each other, and they are hydrocarbon groups having 1 to 4 carbon atoms.)