To obtain a skin preparation for external use, synergistically reinforcing a humectant action and an action for activating dermal fibroblasts, and exhibiting excellent effects on the prevention and improvement of skin aging syndromes such as the generation of wrinkles and spots and the deterioration of skin elasticity.

This skin preparation for external use contains one or more materials selected from the extract of cultured Agaricus blazei Murill mycelia and the filtrate of the cultured Agaricus blazei Murill mycelia and a sugar mixture isomerized by the action of an alkali hydroxide solution as active ingredients.