The present invention provides a surface-treated powder, wherein at least one compound represented by the general formula (1) adheres to the surface of the powder:wherein R2 is, independently of each other, a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, R4 is, independently of each other, a substituted or unsubstituted, monovalent non-aromatic hydrocarbon group having 1 to 30 carbon atoms, R1 and R0 are, independently of each other, a group selected from aforementioned groups defined for R2 and R4, and R3 is, independently of each other, a group represented by the following formula (2), wherein R0 is as defined above, R5 is a divalent hydrocarbon group having 2 to 8 carbon atoms and R6 is an alkyl group having 1 to 6 carbon atoms, a is an integer of from 0 to 3, b is an integer of from 0 to 200, c is an integer of from 1 to 150, d is an integer of from 0 to 50, provided that when a is 0, d is an integer of from 1 to 50, e is an integer of from 0 to 2 and c/ (b+c+d) is 0.25 or more, and the parenthesized siloxane units may bond randomly or form a block unitFurther, the present invention provides a cosmetic comprising the surface-treated powder and oil. The cosmetic has excellent adhesiveness, forms a uniform cosmetic film which has no color unevenness and has a good coloring property, it does not cause makeup to run with time, is not sticky, gives a good feeling in use, shows stable dispersion of the powder, and the powder therein disperses stably with time. The aforesaid effects are attained even in a cosmetic comprising a mixture of a silicone oil and a polar oil.
