The present invention relates to a cosmetic having the innovative, unprecedented property in which the ultraviolet protection effects do not decrease, but conversely increase, due to coming into contact with moisture such as water or perspiration, and due to heat applied in the usage environment. The cosmetic of the present invention contains
(A) an ultraviolet protectant;
(B) at least one compound that is water-soluble and that has an IOB of 5.0 or lower, selected from among (i) alkylene oxide derivatives and (ii) polyhydric alcohols; and
(C) an oil phase thickener;
wherein the mass ratio of component (A)/component (B) is 20 or lower; and the (B) (i) alkylene oxide derivatives are polyoxyalkylene/polyoxyethylene copolymer dialkyl ethers represented by the following formula (I): R1O—[(AO)m(EO)n]—R2  (I) wherein R1 and R2, each independently, denote a hydrogen atom or a hydrocarbon group having one to four carbon atoms, AO denotes an oxyalkylene group having three or four carbon atoms, EO denotes an oxyethylene group, 1≤m≤70, 1≤n≤70 and m+n≤40.