A compounded rubber, which is made up of an NBR polymer, an organic peroxide and a blowing agent, to which 1 to 100 parts by weight of a synthetic silicic acid serving as a reinforcing filler and 10 to 200 parts by weight of precipitated calcium carbonate having a prismatic particle shape and serving as a filler are added to 100 parts by weight of the NBR polymer, is extrusion molded by a continuous extruder, and heated by HA heating and UHF heating in combination throughout the rubber to cause vulcanization and expansion, thereby providing a thick sponge having a homogenous cell structure. The sponge is passed through press rolls, and the resulting sheet stock is cut or punched with a cutting or punching machine into pieces of a desired form to obtain an applicator for cosmetics.