A silicone composition comprising components (A) to (F), (A) 100 parts by mass of a raw rubber-like, at 25 degrees C, organopolysiloxane having at least two alkenyl groups each bonded to a silicon atom, (B) 5 to 100 parts by mass of silica powder having a specific surface area of 50 m 2 /g or more, (C) platinum or a platinum compound in an amount of 1 to 1,000 ppm by mass as a platinum atom, relative to the mass of component (A), (D) 0.01 to 5 parts by mass of a compound selected from an organic silicon compound having a nitrogen-containing organic group and an unsaturated hydrocarbon group, and benzotriazole and a derivative thereof, (E) an addition reaction curing agent other than said component (C), or an organic peroxide in an effective amount to cure the composition, and (F) 0.01 to 5 parts by mass of an aromatic hydrocarbon group-containing organopolysiloxane represented by the following general formula : (R 1 3 SiO 1/2 ) n1 (R 1 R 2 SiO 2/2 ) n2 (R 3 SiO 3/2 ) n3 (SiO 4/2 ) n4 , wherein R 1 is, independently of each other, a monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms, R 2 is, independently of each other, a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, R 3 is, independently of each other, a monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, wherein a proportion of the number of the monovalent aromatic hydrocarbon group to the total number of the substituents R 1 , R 2 and R 3 is 41 % or more and less than 46 %, n1 is an integer of from 2 to 5, n2 is an integer of from 15 to 25, a total of n3 and n4 is an integer of from 0 to 3, 0<={n4/(n3+n4)}×100<=5, and a total of n1, n2, n3 and n4 is an integer of from 17 to 30. (A) 100 parts by mass of a raw rubber-like, at 25 degrees C, organopolysiloxane having at least two alkenyl groups each bonded to a silicon atom, (B) 5 to 100 parts by mass of silica powder having a specific surface area of 50 m 2 /g or more, (C) platinum or a platinum compound in an amount of 1 to 1,000 ppm by mass as a platinum atom, relative to the mass of component (A), (D) 0.01 to 5 parts by mass of a compound selected from an organic silicon compound having a nitrogen-containing organic group and an unsaturated hydrocarbon group, and benzotriazole and a derivative thereof, (E) an addition reaction curing agent other than said component (C), or an organic peroxide in an effective amount to cure the composition, and (F) 0.01 to 5 parts by mass of an aromatic hydrocarbon group-containing organopolysiloxane represented by the following general formula : (R 1 3 SiO 1/2 ) n1 (R 1 R 2 SiO 2/2 ) n2 (R 3 SiO 3/2 ) n3 (SiO 4/2 ) n4 , wherein R 1 is, independently of each other, a monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms, R 2 is, independently of each other, a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, R 3 is, independently of each other, a monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, wherein a proportion of the number of the monovalent aromatic hydrocarbon group to the total number of the substituents R 1 , R 2 and R 3 is 41 % or more and less than 46 %, n1 is an integer of from 2 to 5, n2 is an integer of from 15 to 25, a total of n3 and n4 is an integer of from 0 to 3, 0<={n4/(n3+n4)}×100<=5, and a total of n1, n2, n3 and n4 is an integer of from 17 to 30. <EOS>